Hair Loss (Effluvium) and Types

Medically Reviewed by Zilpah Sheikh, MD on December 12, 2023
7 min read

Two types of hair loss conditions have "effluvium" in their names: telogen effluvium and anagen effluvium. Both result in hair loss caused by things like stress, illness, pregnancy, surgery, medications, and malnutrition. 

The main difference between the two types is when they happen in the hair growth cycle. Telogen effluvium happens in the telogen, or resting, phase of the hair growth cycle; anagen effluvium happens in the anagen phase, when your hair is growing. Anagen effluvium causes a lot of hair loss very quickly, while telogen effluvium is usually a more gradual thinning. Both types of hair loss are temporary, except in rare cases.

Your hair grows in cycles. Sometimes it is actively growing (anagen phase), and sometimes it is resting (telogen phase). In the resting phase, no new hair grows. It is also normal for hair to shed during this phase. At any given time, you have a small amount of hair in the telogen phase. The rest is in the anagen phase.

Telogen effluvium happens when there is some sort of shock or stress that causes your hair to enter the resting phase too soon. This could be psychological stress from a traumatic event, or it could be the physical effects of a medication, surgery, or nutrient deficiency. When this happens, more of your hair than usual is in the resting phase. This increases shedding and, combined with the lack of new growth, causes noticeable hair loss.

Hair loss from telogen effluvium usually shows up 2 to 3 months after the stressful experience, surgery, medication, or other change to your body that caused it. It appears gradually and is diffuse, or spread over a wide area. You might notice a general thinning of your hair rather than losing clumps of hair or having patchy bald spots. 

With telogen effluvium, you won't lose all the hair on your head. But it can become very thin. Although rare, you might notice hair loss in other areas like your eyebrows or pubic region. In any case, telogen effluvium is not permanent, and most people grow all their hair back once their body has recovered.



Telogen effluvium is caused by some sort of stress or change that causes a reaction in the body, such as:

  • Pregnancy and childbirth
  • Intense psychological stress
  • Major surgery
  • Restrictive diets low in protein 
  • Nutrient deficiencies
  • Severe infection
  • High fever
  • Some medications, such as retinoids, depression medications, nonsteroidal anti-inflammatory drugs (NSAIDs), calcium channel blockers, and beta-blockers
  • Hypothyroidism and hyperthyroidism
  • Stopping birth control pills

The only symptom of telogen effluvium is hair loss. You may notice more hairs than usual in your brush, on your pillow, or in your shower drain. You may notice visible thinning of your hair.

Telogen effluvium doesn’t cause symptoms like flaking, itching, pain, or a rash. Your scalp should look normal.

Telogen effluvium treatment depends on what caused it. If it happened after a surgery or stressful event, the hair follicles will recover in time, and your hair will start growing again. If it was a medication that caused your hair loss, your doctor may recommend stopping the medication or lowering the dose. In the case of nutritional deficiency, eating a better diet or taking a supplement will fix the problem, but it will take some time for that to happen.  

Your doctor may also recommend minoxidil, a medication that can help stimulate new hair growth. It's available over the counter in a formula you apply to your scalp. You can also take it orally, but you'll need a prescription for that. 


Anagen effluvium is similar to telogen effluvium, but it happens much more quickly and can cause you to lose all your hair. Anagen effluvium is common if you're having chemotherapy to treat cancer. These types of cytotoxic drugs control the growth of cancer cells, but they also stop other cells from growing – including in the hair follicles and hair shafts. 

The effects of these drugs are very quick, and your hair will begin to fall out while it is still in the growth, or anagen, phase. It's common for your hair to fall out over a period of days to weeks. You may lose some or all of your hair. You might also lose hair in other areas, such as your eyebrows, armpits, and pubic area. As with telogen effluvium, the loss is usually temporary, and your hair will grow back. 

Chemotherapy drugs are the most common cause of anagen effluvium. You might also have anagen effluvium if you:

  • Ingest a toxic substance, such as arsenic
  • Have radiation treatment (in the scalp area)
  • Get a scalp infection
  • Have an autoimmune disease

Anagen effluvium causes faster and more dramatic hair loss than telogen effluvium. Your hair may fall out in clumps or thin more slowly. You may be able to pull clumps out of your scalp, or you may notice much more hair on your pillow, in your brush, or collecting in your shower drain.

Some people lose all of their hair within a few weeks to months. Others have only patches of hair loss or thinning on their scalp. 

You shouldn’t see any redness, flaking, scarring, or color changes on your scalp. But your scalp may feel sore.

Treatment for anagen effluvium depends on its cause. In most cases, your hair will start to grow again after your chemotherapy is over. Your hair might start to grow again even if your chemotherapy continues. The same is true if your hair loss is caused by radiation. 

If your hair loss is caused by exposure to a toxic substance, it should start growing again after the substance is cleared from your body. If an infection or autoimmune diseases is the cause, your doctor will work to find a treatment for the condition that should help your body begin to regrow hair. 

Scalp hypothermia is one technique that research shows could help prevent some or all of your hair from falling out during chemotherapy. You can wear a special scalp cooling cap before, during, and after your treatment, which may help block the chemotherapy drugs from reaching your hair follicles. How well this works depends on several things, including the type of chemotherapy drug you're getting. There are pros and cons of using these caps, and you should discuss it with your doctor before making a decision.

You can also use topical or oral minoxidil to help stimulate hair growth. Your doctor can tell you if it's safe for you to use based on your condition. 


Your doctor may ask you to collect your hair for 24 hours before your visit. Losing more than 100 hairs in a day is a sign of effluvium.

At the visit, your doctor will ask what medicines you take and whether you were sick or stressed in the 3 months before the hair loss started. They will examine your scalp for signs of hair loss. It may be hard for the doctor to see effluvium if you haven’t lost much hair. 

The “pull test” helps to confirm the diagnosis. Your doctor gently pulls on a section of your hair. Normally, only two to three hairs should come out. If you have telogen effluvium, at least four hairs will come out with each pull. 

An exam alone should be enough to diagnose effluvium. If your doctor thinks a hormone problem, vitamin deficiency, or infection caused your hair loss, a blood test can help confirm the cause. 

A scalp biopsy is the most accurate way to confirm an effluvium diagnosis, although doctors rarely use it. During a biopsy, the doctor removes a small sample of skin from your scalp and sends it to a lab for tests.

How is telogen effluvium diagnosed?

Doctors can diagnose telogen effluvium just by looking for signs of hair loss on the scalp and doing a “pull test.” Blood tests rule out other causes, like hormone problems or a vitamin deficiency. A scalp biopsy can confirm the diagnosis, but most people don’t need one.

How long does telogen effluvium last?

Once you treat the cause, your hair should start to grow in again within 6 months. Because hair grows slowly, it could take longer for your scalp to fill in. 

How can I reduce my risk of developing telogen effluvium?

Take care of your overall health: 

  • Get enough nutrients that promote hair growth, including biotin, zinc, and vitamins A, B, C, D, and E. 
  • Eat at least 40 grams of protein each day. 
  • Aim for 7 to 9 hours of sleep every night. 
  • Reduce stress with techniques like meditation, deep breathing, and yoga.

Be extra careful with your hair:

  • Use a gentle shampoo. 
  • Avoid high-heat products like curling irons and flatirons. 
  • Put your blow dryer on the lowest heat setting. 
  • Comb and brush your hair carefully. 
  • Have color, perms, or other treatments done at a salon that knows how to protect your hair from damage.