Anagen Effluvium

Anagen effluvium is a sudden and widespread type of hair loss. It happens when there’s a disruption to your normal hair growth cycle.

There are three hair growth phases. The anagen phase is the active growth stage. Anagen effluvium happens when you lose hairs that are in the active growing phase. It’s usually caused by damage to your hair follicle.

Anagen effluvium can cause complete hair loss on your scalp. It may also affect hair on your body, face, eyebrows and eyelashes.

This condition is the most common side effect of chemotherapy, and affects more than half of all people who get this treatment. In most cases, anagen effluvium is temporary, but it may increase the risk of permanent hair loss. Those high-risk instances include high dosages of chemotherapy and certain chemotherapy regimens.

Anagen effluvium signs

You may notice signs starting about two weeks after something triggers the condition:

• Sudden, rapid hair loss
• Thinning hair on your scalp (sometimes eyebrows, eyelashes or body hair)
• Hair strands that break easily
• Keeping hair along your hairline while the rest of your scalp thins or sheds
• No skin discoloration

Over time, this may lead to bald patches or complete hair loss in areas where hair normally grows.

Anagen effluvium causes

Anagen effluvium happens when something suddenly stops your hair cells from dividing and growing.

These cells, called hair matrix cells, sit at the base of each hair follicle. They’re some of the fastest-growing cells in your body.

When they stop working, new hair can’t form properly. The hair becomes thin and weak, then breaks off near your scalp and falls out quickly.

Common causes or triggers of anagen effluvium include:

• Chemotherapy: Chemotherapy drugs destroy cancer cells. It can also affect other fast-growing cells in your body. This includes the cells that help your hair grow.
• Heavy metal poisoning: Exposure to toxic metals, like thallium, mercury, boron, copper and cadmium, can damage hair follicles.
• Radiation exposure: Radiation therapy or accidental high-dose exposure can cause hair loss.
• Inflammatory and autoimmune diseases: Conditions like alopecia areata, syphilis and pemphigus vulgaris can attack your hair bulb or follicle.
• Surgery: It can follow scalp-related surgeries, like mole removal or scalp grafting.

Several non-cancer drugs can also cause it, including:

• Albendazole
• Colchicine
• Cyclosporine
• Isoniazid
• Levodopa
• Methotrexate

Risk factors

Hair follicles tend to be more fragile with age, so anagen effluvium is more common after age 65. You also may be more at risk if you have or have had:

• Graft vs. host disease after transplant: This condition can damage hair follicles and increase the risk of hair loss when you have chemotherapy.
• Hair loss: If you already have androgenetic alopecia (hereditary thinning or balding), you may have worse hair loss.
• Liver problems: When your liver doesn’t break down chemo drugs properly, the medicine can build up in your body and cause more severe hair loss.
• Previous chemotherapy-related hair loss: If you lost hair from past chemo, you’re more likely to have it happen again.
• Previous scalp radiation: If you had a history of radiation therapy to your scalp, you’re more likely to lose hair again with chemo.

Complications of anagen effluvium

Losing your hair suddenly can be emotionally overwhelming. Finding clumps of hair in your brush, the shower drain or on your pillow can be upsetting and hard to process. While anagen effluvium doesn’t cause physical pain, it can deeply affect your mental and emotional well-being. Many people feel stress, anxiety or depression, or begin to see themselves differently after hair loss.

How doctors diagnose anagen effluvium

Your healthcare provider can usually diagnose anagen effluvium after a thorough clinical history and physical exam. A key finding in the clinical history is sudden hair loss days to weeks after a known exposure.

During the exam, your provider will check your scalp and hair for signs that point to anagen effluvium. They’ll look for broken hairs and make sure there’s no discoloration, scarring or scaling on your scalp.

If they need more information, your provider may:

• Look at hairs under a microscope: This shows whether the hairs are breaking during the growth phase.
• Use a magnifying tool: This gives a close-up view of your scalp and hair roots.
• Order a scalp biopsy: If the diagnosis isn’t clear, a small skin sample from your scalp can rule out other conditions.
• Do blood tests: These check for other possible causes of hair loss, like thyroid issues, iron deficiency or autoimmune diseases.

In most cases, your provider can confirm anagen effluvium without many tests. But if they suspect another condition is involved, these extra steps can help find the cause and guide treatment.

Anagen effluvium treatment

Treatment for anagen effluvium focuses on helping hair grow back and supporting your emotional well-being during recovery.

Here are some options your provider might discuss with you:

• Planning ahead: Your provider may suggest getting a wig, scarf or head covering before hair loss begins. These can help protect your scalp, keep you warm and boost confidence.
• Scalp care: Use gentle shampoos and soft brushes and avoid harsh hair products or heat styling. These steps may protect new hair growth as it returns.
• Mental health support: Hair loss can deeply affect self-esteem and body image. Counseling, support groups and connecting with others who’ve gone through similar experiences can make a big difference.

Anagen effluvium medication

There isn’t a medication that can stop hair loss completely. But there are options available to help your hair regrow, like minoxidil for example. Providers are also studying how light therapy (photobiomodulation therapy) may help with hair regrowth. 

Is anagen effluvium reversible?

Yes, anagen effluvium is usually temporary. Hair typically starts to grow back a few weeks after treatment ends or contact with a trigger stops. But there are a few cases where hair loss is permanent. This is usually with high doses of chemotherapy.

When should I see my healthcare provider?

Contact your healthcare provider if you notice sudden or significant hair loss. Be sure to tell them about any new medications or treatments you started. This is helpful, as hair loss can sometimes be a medication side effect.

If you’re receiving cancer treatment, let your provider know right away if you notice new or worsening symptoms, like skin irritation, discoloration or swelling.

After treatment ends, continue regular follow-up visits. If your hair isn’t growing back as expected, talk with your care team. They can help you find ways to support your recovery and manage any concerns.

What questions should I ask my healthcare provider?

If you have anagen effluvium, you may want to ask your provider:

• What are my treatment options?
• Are there any side effects to the treatments?
• When should I expect my hair to grow back?
• Can you recommend mental health resources?

What can I expect if I have anagen effluvium?

Anagen effluvium may happen over just a few weeks. This can be a difficult and emotional experience. But hair loss is almost always temporary. Regrowth is expected once what’s causing it stops.

At first, your hair might look or feel a little different. For example, it may be softer, curlier or a slightly different color. Most people notice steady changes within a few months.

It’s normal to feel anxious or discouraged during this time, but the outlook is positive. Your healthcare provider can help guide you through this process and suggest ways to support healthy regrowth. They can also help you cope with the changes while your hair returns.

How long does anagen effluvium last?

Hair often starts to grow back within one to three months after stopping the trigger that caused it. Many people see full regrowth within three to six months, but it can take up to a year.

Can anagen effluvium be prevented?

There’s no way to completely prevent anagen effluvium.

If you’re receiving chemotherapy, your provider may suggest scalp cooling (also called cold caps). This device gently lowers the temperature of your scalp during treatment. Cooling slows how much medication reaches your hair follicles. This may reduce hair loss.

Scalp cooling isn’t right for everyone. Your provider will discuss whether it’s a safe option for you.