What is Telogen Effluvium and Why is My Hair Suddenly Shedding?

Key Takeaways:

• What is telogen effluvium? Telogen effluvium is a sudden, temporary, and generalised hair loss affecting the entire scalp, usually caused by some form of stress to the body.
  
• What causes it?  It is usually caused by a physical or emotional stressor on the body.
  
• Does the hair grow back? Telogen effluvium is a temporary form of hair shedding. If you have telogen effluvium, your hair is expected to grow back as normal within a few months.
  
• How is it different from pattern hair loss? It differs from pattern hair loss as it is diffuse rather than in a targeted area and is usually temporary in nature rather than progressive.
  
• What should I do? If you are concerned about your recent hair loss, contact your GP for an assessment and further guidance.

If you have recently noticed you are shedding more hair from your head than usual, you may have a condition called telogen effluvium. In this article, we will discuss its symptoms, causes, and treatment.

What Is Telogen Effluvium?

Telogen effluvium, also known as stress shedding, is a type of hair loss that occurs all over the scalp. When the body is under high physical or mental stress, hairs in the resting phase (telogen phase) are shed much quicker than usual. What you may notice is a loss of your hair volume or density rather than areas of bald patches.

“In telogen effluvium, what you may notice is a loss of your hair volume or density rather than areas of bald patches. It is typical for the condition to present as shedding of hair rather than active areas of recession or bald patches appearing. If you do see areas of balding, then it suggests another condition, which you will need to see your GP or hair loss specialist for further evaluation.”

Dr Bijaya Laxmi Gurung, Surgeon at The Treatment Rooms London 

What Causes Telogen Effluvium?

Telogen effluvium is a physical manifestation of the body’s response to a stressor. That stressor can be caused by physical stress, life events, hormonal changes, or medications. 

On average, close to 9 in 10 of our hairs are in an active growing phase at any given time. The rest are in a state of dormancy or preparing to shed. Telogen effluvium is when stress on the body places a large number of hairs in the resting phase of hair growth.¹

• Physical stress, especially with a fever, severe infections, major surgery, or trauma, can bring on hair shedding.¹  This was seen at much higher rates during the COVID-19 pandemic, for example.²
  
• Hormonal changes can trigger sudden hair release. This includes after childbirth (postpartum hair loss), after stopping hormonal medications such as contraception, and with metabolic hormone changes such as thyroid hormone level shifts.
  
• Nutritional: A decrease in nutritional intake, such as rapid weight loss attempts, crash or restrictive diets, including poor nutrition from certain medical conditions, can cause hair loss. Any deficiency in nutrients such as iron, vitamin D, or B12 usually has the same effect. 
  
• Psychological stress: Emotional stress or difficult life events can increase production of stress hormones like cortisol and increase the amount of hair that falls out.³
  
• Medications may trigger sudden hair loss; these may include certain blood thinners, blood pressure medications, and antidepressants. You may also undergo shedding of hair if you abruptly start or stop contraceptive medications.⁴ The important thing to remember is to discuss any issues of hair shedding or side effects with the doctor who prescribed your medications before deciding to stop or change any of them.
  

Even though it is natural to want to understand what caused this sudden hair loss, a definite trigger cannot always be found. The good news is that telogen effluvium is short-lived in most cases. However, in a minority of people, it can remain persistent for over 6 months, at which point it is called chronic telogen effluvium. 

Signs and Symptoms

The main symptom you will experience in telogen effluvium is a noticeable increase in the amount of hair that you are shedding. It is not common for you to have any other symptoms alongside this. Oftentimes, there is a delay between the event that triggered the hair loss and you actually noticing it. For this reason, you may not be able to make the connection between the trigger and the loss itself.¹

Does Telogen Effluvium Grow Back? 

Telogen effluvium is temporary and usually lasts for a short period of less than 6 months. It tends to regrow on its own without any intervention.

Dealing with known triggers, for example, the removal of stress, recovery from an illness or operation, balancing your hormonal levels, or correcting dietary deficiencies can all contribute to your hair cycle returning back to normal.

“Telogen effluvium, in most cases, is a self-limiting condition that rarely persists longer than 6 months. The majority of our cases in our clinic will recover and they can help lessen the amount of hair fall by using Minoxidil. If you are worried about the shedding you are seeing, please reach out. It is often caused by a stressful event 6-7 months prior which, if resolved, should mean the hair loss will stop too.”

Dr Bijaya Laxmi Gurung, Surgeon at The Treatment Rooms London

What is the difference between Telogen Effluvium and Other Hair Loss? 

You may mistake telogen effluvium for other causes of hair loss. To clear any confusion, the main conditions that may present as similar are distinguished below.

How to tell the difference between telogen effluvium:

• vs Androgenetic (pattern) hair loss: Androgenetic alopecia is commonly referred to as pattern hair loss. It is what typically affects men who are balding. The main difference is that in telogen effluvium, the hair loss is diffuse and random, whereas in pattern hair loss there is a particular part of the hair that is most affected, for example, the temples and frontal hairline in men and the crown area in women. There will also be shorter and thinner hairs present in androgenetic alopecia.

• vs Alopecia areata Incognita: This is a subtype of autoimmune hair loss that will present similarly to telogen effluvium, especially in regard to the rapid onset of widespread hair loss with no patchy areas. The difference is that in alopecia areata incognita, you may experience other symptoms such as pain or tingling of the scalp and nail changes alongside the hair loss. A biopsy will also show microscopic findings of inflammation, which will not be the case for telogen effluvium.²

• vs. Anagen effluvium. Anagen effluvium is usually a result of medical treatments for cancer such as chemotherapy. It causes hairs that are in their growing phase (Anagen) to fall out. You will likely be made aware that your hair will fall out before it happens. In telogen effluvium, the hair loss is usually unaccounted for and affects the follicle on a different phase of the hair growth cycle. ⁴

Diagnosis

Diagnosis of telogen effluvium can typically be made with a detailed account of the history of the hair loss, such as taking note of the onset, distribution, and association to any recent physical or medication changes. 

Together with a detailed history, your Doctor may perform a physical examination of the scalp to identify other variables such as signs of inflammation, any lumps and bumps, or discharge.

If you need further investigation, you may be recommended blood testing for hormonal conditions or nutrient deficiencies. These blood tests may include checks of your thyroid hormone levels or for iron and other nutrient deficiencies.¹

Your doctor may also carry out some simple tests such as a pull test and a wash test:

1. A pull test is where a gentle pull on the hair is carried out to see if more comes out than usual.

2. A wash test is performed by you at home. You will be asked to go 5 days without washing your hair. After that time, you will be asked to cover your sink with a strainer to catch any hairs that fall out while you wash your head. The number of hairs captured gives an indication as to whether you have increased shedding or not.

If the diagnosis is uncertain, it could be possible that a small sample of your scalp (biopsy) may be taken for further inspection under a microscope. 

Treatment

There is no further treatment needed after the causative event or stressor has been identified and managed. If no cause can be found, the hair loss is still expected to be temporary and hair growth will resume without further intervention. 

Examples of interventions that can improve the condition are:

• Correcting hormonal imbalances
• Improving low vitamin D, vitamin B12, zinc or iron levels.⁵
• Changing or withdrawing the medication that precipitated it, under your doctor’s supervision.

If the condition is chronic, i.e it lasts longer than 6 months, then you may be given some medical treatment for hair loss. The most likely medication you will be given is minoxidil.

This is known to stimulate hairs into an active growth phase from a resting state. It is not specifically proven to work in the case of telogen effluvium, but might provide some benefit as it can reduce shedding and stimulate new hair growth, potentially allowing you to recover lost density from chronic shedding.⁶

Can You Have a Hair Transplant for Telogen Effluvium?

No. A hair transplant is not appropriate for someone with active telogen effluvium. This is because the condition is usually only temporary and there is no permanent hair loss that needs restoration. Performing a hair transplant risks damaging the native hairs which have just been shed. 

When to See a Health Professional

Seek out advice if your hair loss follows the same pattern as telogen effluvium but is accompanied by the following:

• Severe or rapidly worsening shedding
• Shedding continues for more than 6 months
• Hair loss is patchy rather than evenly spread across the scalp
• Your scalp is red, itchy or inflamed
• You have general symptoms like fatigue, weakness or unexplained weight changes
• Your hair loss began after starting or changing a medication

Your GP or hair loss specialist will be able to investigate these symptoms and provide further guidance.

Conclusion

Telogen effluvium can be concerning as it involves hair shedding over a diffuse area of your scalp. Seek an assessment with a qualified healthcare professional if you are concerned to rule out any other potential causes. It is generally considered a self-limiting condition, and your hair should be back to normal within a few months.

References 

1. Hughes EC, Syed HA, Saleh D. Telogen effluvium. [Updated 2024 May 1]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2026. Available from: https://www.ncbi.nlm.nih.gov/books/NBK430848/ 
   
2. Jimeno Ortega I, Stefanato CM. Telogen effluvium: a 360 degree review. Ital J Dermatol Venerol. 2023 Dec;158(6):457-66. doi: 10.23736/S2784-8671.23.07579-5. 
   
3. British Association of Dermatologists. Telogen effluvium [Internet]. London: British Association of Dermatologists; 2013 [updated 2025 Oct; cited 2026 Aug 12]. Available from: https://www.bad.org.uk/pils/telogen-effluvium
   
4. Dyall-Smith D. Alopecia from drugs [Internet]. DermNet; 2009 [cited 2026 Aug 12]. Available from: https://dermnetnz.org/topics/alopecia-from-drugs 
   
5. Almohanna HM, Ahmed AA, Tsatalis JP, Tosti A. The Role of Vitamins and Minerals in Hair Loss: A Review. Dermatol Ther (Heidelb) 2019;9:51–70. 
   
6. Mysore V, Parthasaradhi A, Kharkar RD, Ghoshal AK, Ganjoo A, Ravichandran G, et al. Expert consensus on the management of Telogen Effluvium in India. Int J Trichology. 2019;11(3):107–112. doi:10.4103/ijt.ijt_23_19. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6580807/