What is the cause of sudden hair loss?

What is the cause of sudden hair loss?

Hair loss is inevitable with age. In today's life, due to various reasons, including changes in lifestyle, diets and stress, hair loss in some people (especially men) starts at a younger age, which may be scary for some people.

But scarier than premature hair loss is sudden hair loss. It means that a person who did not have any problem in terms of hair loss until some time ago, in a short period of time suddenly loses a part or all of his hair. In this article, we will examine causes of sudden hair loss.

In general, daily shedding of up to 100 hairs is considered normal in humans. This hair loss mostly happens when combing hair, bathing or sleeping. In a young person, at the same time as a hair falls out, with activity of hair follicles, a new hair is replaced in same place. In fact, naturally, there is a balance between hair shedding and hair growth. Therefore, baldness is not usually seen in young people.

With age, due to physiological and genetic reasons, the balance between shedding and growth is disrupted and many people suffer from mild to severe baldness. Most baldness is male and female pattern hair loss or androgenetic alopecia. Baldness is also called genetic hair loss.

So, in general, we all have hair shedding; however, shed hairs are replaced. When the balance between hair shedding and growth is disturbed, we say that a person has hair loss.


Hair loss vs hair shedding

Usually, it's normal to shed daily about 100 hair strands. But losing more than normal might be a sign of hair loss. Notice that Unlike hair shedding, hair loss is alarming and usually needs medical attention.

What is hair loss?

Usually, hair loss occurs mainly because of external factors. Hair loss occurs when something prevents hair from growing. The medical term for this is anagen effluvium. Anagen effluvium is the abrupt loss of hairs that are in their growing phase due to an event that impairs the mitotic or metabolic activity of the hair follicle. While hair loss is reversible, hair regrowth can take around 1-3 months and in extreme cases, it can even lead to permanent alopecia.

What is hair shedding?

Unlike hair loss which is not normal, hair shedding is a normal part of the hair cycle. Each person has around 100,000 hair follicles on head. Based on the life cycle of the hair follicles, an average person loses about 100 hair strands daily. So, don’t worry This is a healthy loss and doesn’t point towards any problem. Sometimes, factors like stress can cause excessive hair shedding. In this case, you shed more than 100 strands per day.

What is the cause of sudden hair loss?

What is sudden hair loss?

Hair loss is generally more common among men than women. However, hair loss is also common in women. So that it is said that about 37% of women under 50 suffer from hair loss.

The process of hair loss can be gradual or sudden. If the hair loss is gradual, the person will gradually notice an increase in hair strands compared to before. If this process continues, it may cause baldness. But in sudden type, hair loss begins in a short period of time, and interval between the beginning of hair loss and the appearance of baldness will be short.

Note that hair loss affects not only the beauty aspects, but also the psychological aspects. Because a person suffering from hair loss may avoid participating in many professional, educational, recreational and social occasions because of the discomfort and embarrassment of their hair. This avoidance will continue until the hair loss is resolved, which may even take months. This issue will gradually reduce self-confidence and start psychological problems.

The most common causes of sudden hair loss

Androgenic alopecia

In many cases, the main reason for hair loss is androgenetic alopecia. Androgenetic alopecia usually happens gradually; but it can also be one of the reasons for sudden hair loss. In this type of baldness, genetic and hormonal factors play an important role:

Androgenic alopecia | What is the cause of sudden hair loss?

Genetic factors: If there is a history of hair loss and baldness in your father, uncle, uncle or other relatives, the probability of this happening in you is higher than normal. Therefore, when visiting clinic, the attending physician will definitely ask you about your family history of hair loss at a young age.

Hormonal factors: Testosterone and Dihydrotestosterone are present in both men and women, but their amount is higher in men's bodies. Increase in the level of these hormones in each person's body compared to normal state for him is related to increase in the amount of hair loss. For this reason, requesting a blood test to check the level of hormones is one of measures to investigate cause of sudden hair loss.

Unfortunately, there is no cure for androgenetic alopecia. Of course, drugs such as minoxidil and finasteride can be effective in postponing baldness, but to compensate for lost hair, the only treatment is hair transplantation.

Improper diet

As mentioned, the creation of new hair strands takes place in the hair follicles. For this, various substances are needed, the lack of which can cause sudden hair loss.

Maybe you have also heard that a person suffered sudden hair loss due to following an unprincipled diet. Usually, in case of these people, we see that with a little stretching, bunches of hair strands are separated from head.

Hair fibers are made of protein. For this reason, the lack of protein in the diet can cause sudden hair loss. Sources of protein in the diet include all types of meat (fish, chicken and red meat), eggs and dairy products.

foods that can prevent hair loss

Various vitamins are also needed to make hair strands, the most important of which are B vitamins, especially niacin and biotin. So that most of medicines, supplements and hair strengthening shampoos contain these vitamins.

The presence of some minerals is also necessary in the process of making hair strands. In addition to causing anemia, iron deficiency can cause sudden hair loss. Calcium and magnesium, which are abundant in dairy products, are present and important in the reactions of making hair strands. Zinc is one of the other materials needed to make hair strands. Lack of any of the mentioned elements can cause hair loss.

Sudden hair loss due to improper nutrition is more common in people who suffer from malabsorption problems (such as gastrointestinal diseases) or who follow non-original weight loss diets.

Hair loss due to improper diet is usually treated by itself by eliminating body deficiencies and does not require other therapeutic interventions.

Telogen effluvium

In order to better understand the complication of telogen effluvium, we must first review the stages of hair growth. The life cycle of hair strands has three stages:

  • Anagen phase or growth phase: In this phase, hair growth occurs. Anagen usually lasts for about 3 years, and on average, 90% of a person's hair is in the Anagen stage.
  • Catagen stage or temporary phase: Catagen is a transitory and temporary stage and is like a bridge between Anagen and Telogen stage. This phase usually lasts less than three weeks. Only about 1% of healthy individual hairs are in this stage of hair loss.
  • Telogen phase or resting phase: In this phase, hair strands will not grow anymore. This stage lasts for about 3 months and on average 10% of a person's hair is in this stage. At the end of the telogen phase, the hair shaft separates from the hair bulb and falls out.
stages of hair growth

In telogen effluvium disease, for the reasons that will be mentioned later, the hair strands go through the Anagen and Catagen phases faster and as a result, a higher percentage of hairs are in the telogen phase. For this reason, the rate of hair loss increases. That means, for example, instead of 100 hairs, 400 hairs fall daily. Telogen effluvium is one of the leading causes of sudden hair loss.

Telogen effluvium can be caused by various reasons. All these reasons have a common basis; It is the introduction of severe stress to the body. This stress can be due to mental issues, physical diseases, sudden changes and injuries.

An important point is that facing a severe stress does not immediately cause hair loss. Severe stress reduces the production of new hair strands by suppressing the activity of hair producing cells. It also increases the speed of passing through growth phase or Anagen. We know that hair loss occurs when the Catagen and telogen phases are completed; which takes 3-4 months altogether. In this way, about 3 months after a severe stress, sudden hair loss begins.

Examples of stress that can cause sudden hair loss:

  • Severe stress
  • Improper diet
  • High fever
  • Severe physical injuries
  • Sudden weight loss
  • Stress
  • Amputation
  • Critical life events such as separation or loss of loved ones

Telogen effluvium usually heals on its own after the cause of stress is removed and does not require medication or other therapeutic interventions.

Taking some medications

Sudden hair loss can be caused by various medications. The list of medications that can cause hair loss is long. If you have recently started taking medication and your hair loss has increased since then, discuss this with your doctor. In many cases, another alternative medicine can be used. Hair loss that is caused by a drug complication usually resolves within a few months after stopping the drug and hair will be back to normal.

The most famous drugs that cause sudden hair loss include the following:

Chemotherapy drugs

Perhaps the most famous drugs that cause hair loss are chemotherapy drugs. These drugs inhibit the division of cells to prevent the growth of cancer cells. Of course, they do not inhibit the division of all cells, they only inhibit the division of cells that have a high rate of reproduction.

Chemotherapy drugs | What is the cause of sudden hair loss?

In addition to cancer cells, hair follicle cells also have a high rate of division. For this reason, one of unwanted effects of these drugs is preventing cell division in hair follicles. As you know, hair follicles are the place where new hair strands are made, and if cell division is inhibited in them, new hair strands will not be made.

Contraceptive drugs

As mentioned, changes in sex hormone levels can cause sudden hair loss. Contraceptive drugs also cause changes in the balance between sex hormones. Therefore, hair loss may occur while taking these drugs.

Hair loss after pregnancy

Hair loss after childbirth or breastfeeding is one of most common complaints of mothers and one of reasons for sudden hair loss. During pregnancy, the level of sex hormones estrogen and progesterone in mother's body is high, and after delivery, the level of these hormones decreases significantly. This change causes the hair follicles, which are makers of hair strands, to enter resting phase. For this reason, after each hair falls, there will be no replacement hair for it, and mother's hair will be sparse after giving birth.

The important thing is that mother should not worry at all, because with passage of time and usually during first year after giving birth, the situation will improve and mother's hair will be like before pregnancy.

Getting some diseases

Various diseases can cause sudden hair loss, some of which we will examine below:


Some infections can cause sudden hair loss. The most common of them are fungal infections, which are mostly observed in children, teenagers and people with weak immune system. The prevalence of fungal infections in healthy adults is low.

Tinea capitis is a fungal disease caused by a group of fungi called dermatophytes. Warm and humid environments are favorable for growth of these fungi; for this reason, the scalp and hair are a suitable habitat for them.

The most prominent symptom of this disease is sudden hair loss. The place of hair loss may be painful. This disease is easily transmitted from person to person. Using an infected hat, towel and comb is one of the ways to transmit this disease.

The treatment of this fungal infection is by taking antifungal drugs such as griseofulvin, terbinafine or fluconazole for 4 to 6 weeks. Hair loss is usually reversible with treatment. Other infections that can cause sudden hair loss include folliculitis. In this disease, inflammation occurs in the hair follicles. So after hair loss, replacement hair will not grow and that area will be bald.

Thyroid diseases

Sudden hair loss can be a sign of hypothyroidism. Hypothyroidism will have other symptoms such as weakness and fatigue, obesity and facial puffiness, slow movements and reflexes, and dry skin. If your doctor suspects this disease, a blood test is helpful for diagnosis.

Thyroid diseases | What is the cause of sudden hair loss?


Trichotillomania is a mental disorder that affects both men and women. This disorder is more common among young girls.

In Trichotillomania, a person obsessively pulls out their hair. During physical examination, the doctor will suspect this disease by observing the way hair grows and some other clues. Both drug and psychotherapy methods can be used to treat this disease.

Lupus disease

Lupus disease | What is the cause of sudden hair loss?

Lupus disease is best known by the red skin lesions that appear in shape of a butterfly on nose and cheeks. This disease is an autoimmune disease in which the immune system mistakenly attacks and damages body's cells. In lupus, the scalp may also be affected and coin-shaped areas may experience sudden hair loss.

Lupus is more common in women than men. Hair loss caused by this disease can be temporary or permanent depending on the severity of disease and its type.

Alopecia areata

Alopecia areata

Alopecia areata, like lupus, is an autoimmune disease. In lupus, the whole body is involved, and in alopecia areata, the immune cells attack only hair follicles.

Alopecia areata usually causes sudden hair loss with defined boundaries and in form of small circular areas. Of course, it can cause the loss of all head hair or even all body hair. In these cases, it is called alopecia totalis and universalis.

Sudden hair loss caused by alopecia areata usually resolves on its own. In more severe cases, the treatment of disease is performed by a dermatologist by local corticosteroid injection.

Polycystic ovary syndrome (PCOS)

Polycystic ovary syndrome (PCOS)

Polycystic ovary syndrome, which is also called PCOS, is a disease seen only in women and causes a disturbance in balance of their sex hormones.

As we mentioned earlier, the imbalance of sex hormones can cause sudden or gradual hair loss. Of course, polycystic ovary syndrome causes more hair in different parts of body than it causes hair loss.

FAQ about sudden hair loss

 Can ovary syndrome cause hair loss?

Polycystic ovary syndrome causes hair loss. This syndrome in women causes menstrual irregularity, purulent pimples, oily skin and increased excess body hair and hair loss. Birth control pills are the most common treatment for this syndrome, but they do not cure the disease, but reduce some of symptoms of disease, such as acne and facial hair. It also protects women against uterine cancer.

Medicines such as spironolactone, male anti-hormone drugs, control them by blocking the hormones that cause symptoms such as acne and facial hair. Also, the progestin drug that regulates menstrual cycle and must be taken every month. This drug reduces the risk of uterine cancer. Metformin is one of drugs that help treat this disease. These treatments are somewhat effective for people with male pattern baldness. Minoxidil may also help these people. Some people have a suitable hair bank for hair transplantation and even hair transplantation can be a suitable option for these people.

Is losing hair hereditary?

genetic hair loss

This type of hair loss is more common in men, but in fact, the most common type of hair loss is hereditary hair loss. Male or hereditary hair loss may also be seen in women. In men, hair loss starts from the temples and continues to back, and gradually whole head becomes bald. In women, like a hat they put on their head, the hair in area under hat decreases.

The treatments that are considered for these patients should be continued until end of life. One of these drugs is Finasteride, which is the only oral drug that stops hair loss by 83% and causes hair to grow again by 66%. This medicine is effective for area on head rather than front of head. This drug has side effects in 0.3% of men. Minoxidil is available in concentrations of 2% and 5%, and 5% is prescribed for men. 70% is effective for hair stabilization and 50% for hair regrowth. This solution should be used twice a day. There are other treatments for male hair loss. Low power lasers and sometimes PRP and hair mesotherapy can help.

What is the best treatment for hair loss and thinning?

There are many reasons for hair loss. The most common is heredity. But anemia, stress, infections, internal cancers, hormonal problems such as ovarian cysts in women, hypothyroidism, decreased serum ferritin and physiological shedding after childbirth, discontinuation of oral contraceptives, chemotherapy drugs or psychiatric drugs such as Sodium valproate, anticoagulants such as warfarin and radiotherapy can also cause hair loss.

Some physical activities such as tying hair in a ponytail or improper use of a hair dryer can contribute to hair loss. Therefore, the doctor must examine patient and diagnose the type of hair loss. Sometimes it is necessary to perform a thyroid test and measure the level of vitamins and check the iron ferritin in blood. These cases depend on the doctor's decision.

How do I get rid of oily scalp and hair loss?

Oily and dry hair does not cause hair loss by itself. It means that oily or dry hair is not one of causes of hair loss. For this type of hair, we have to use a special shampoo, and in general, the care of this hair is different, not that it causes hair loss.

What can I take for hair loss while pregnancy or breastfeeding?

Usually, during pregnancy, hair becomes thicker. After giving birth and when baby is born, pregnancy hair loss may start and last for three to four months. This hair loss is a physiological type and usually resolves and does not require special treatment.

Does hypothyroidism affect hair loss?

Hypothyroidism can cause weight gain and fatigue, and hyperthyroidism can lead to weight loss and nervousness. Both hypothyroidism and hyperthyroidism can cause dry and brittle hair and thinning of hair on head and body, which should be treated as main treatment. The doctor makes prescriptions until final treatment.

Can mesotherapy stop hair loss?

Hair mesotherapy is a subcutaneous injection that stimulates mesoderm. Minerals and amino acids, nucleic acids and coenzymes may be injected and can grow hair follicles. It neutralizes effect of testosterone and stimulates blood circulation of skin and controls hair loss. This treatment should be done at discretion of the doctor. Mesotherapy has a limited role and may be combined with other treatments.

How does stress affect your hair loss?

How does stress affect your hair loss?

Each person has between 120,000 and 150,000 hairs. It takes two to three years for these hairs to complete their growth and then enter resting phase. The resting phase lasts up to four months, after which hair falls out and is replaced by new hair. Therefore, according to this pattern, shedding up to 100 hairs per day is normal.

Some severe stress can cause a change in physiological function of body and increase the number of hair strands that are in resting phase. These hairs fall out and person notices their hair loss, while the cause is physiological. People who have physiological changes in their body experience hair loss. In fact, hair loss is one of body's responses to severe physiological stress. Such as diets, medications, lifestyle changes.

The good news is that this shedding is temporary and hair will return to normal. Stresses that cause physiological changes, such as stopping the use of pregnancy drugs, heavy diets with low calories, decrease in amount of estrogen in body following childbirth in women, severe diseases such as high fever can cause hair loss. Major surgeries, severe infections, certain medications and thyroid diseases can cause hair loss. A deficiency as well as an excess of vitamin A can lead to hair loss.

What is the treatment for hormonal hair loss?

In fact, hormonal hair loss is the same as hereditary hair loss, which is most common hair loss in men and women. As we said, there is a range of drug treatments, if it is not effective, we suggest hair transplant. With new hair transplant methods, this type of hair loss can be treated well.

Does childhood anemia affect hair loss in adulthood?

Of course, iron deficiency causes hair loss, and these people must take iron supplements along with vitamin C, which makes iron absorb better.

Can alopecia in beard be cured permanently?

Yes. In alopecia areata, the hair of one part of the head is empty at once. Its most common form is like a coin, but it may include entire head hair. This type of hair loss is treatable in many cases. One of the most common treatment methods is to inject cortisol into hairless areas, which should usually be done by a dermatologist with sufficient expertise.

It may need to be repeated two or three times. Coin hair loss responds well to this type of treatment. In some people, the doctor may prescribe minoxidil 5%, which is one of treatments for hair loss. Anthralin ointment or cream or irritating ointments may be prescribed by doctor and this disease will be treated.

What is the cause of hair loss after bleaching?

Hair color has three stages to be able to sit on hair. First, the cuticle protection on hair must be destroyed by ammonia in its composition so that hair color can enter hair shaft. The second step is to use hydrogen peroxide, which enters cortex and destroys natural hair pigments. In the third stage, pigments in hair color enter cortex. Frequent use of hair bleaching substances can cause irreparable side effects and even lead to hair loss and hair whitening. Therefore, some caution should be used in use of hair bleaching materials.

Can I get finasteride over the counter for hair loss?

Some people use medicines without consulting a doctor. The doctor must examine person. Because not all hair loss can be treated with finasteride and minoxidil and similar drugs.

Do hair supplements effect on hair loss?

Vitamins and amino acids are essential for hair growth. But the vitamins inside shampoos have no effect and are only for advertising. Because these materials are not absorbed in this way and only have an advertising aspect. Shampoo cannot treat hair loss and regrowth. Shampoos only have a hygienic role.

Does stopping minoxidil worsen hair loss?

Minoxidil is used as 5% in men and 2% in women. Usually, once the treatment is started, person should continue taking it for a long time. Stopping its use after three to six months destroys its effect. Minoxidil is more effective on central and scalp areas than on frontal areas. In some cases, the hair transplant specialist uses this solution to complete the hair transplant procedure and help hair grow thicker.


Hi, my name is Aishka, I'm a nurse and also a translator and content developer. We are going to argue about cosmetic surgeries, like rhino, blepharoplasty, hair implant and ….. if there is any question about this topics. don't be shy . just ask.

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