Hair loss after COVID-19

Learn why increased hair shedding can occur after COVID-19 and what you can do if it happens.

A patient arrives at the consultation very concerned. A few months earlier she had COVID-19 and is now noticing that her hair is shedding in large amounts. She may even bring photographs on her phone or collected strands of hair to show the extent of the problem.

Consultations of this kind, more frequent among women but also seen in men, increased considerably during the pandemic. Our dermatologists expert in hair disorders also took part in a study examining the timing and duration of acute telogen effluvium after COVID-19.

Hair loss after COVID-19: why does it happen?

Clinical studies have described an association between COVID-19 and subsequent acute telogen effluvium, a form of diffuse hair shedding that can occur after illness or other physiological stress. The phenomenon cannot necessarily be attributed to a single mechanism. Factors that may contribute include the inflammatory response associated with infection, fever, physiological stress and, in some patients, psychological stress related to the illness and wider circumstances.

More severe systemic illness and episodes of high fever have traditionally been recognised as triggers for telogen effluvium. As Dr Óscar Muñoz explained at the time, similar shedding can occur after other significant illnesses, major surgery and other forms of physiological stress.

To understand why, it is useful to consider the hair cycle. At any given time, most scalp hairs are in the active growth phase, or anagen, while a smaller proportion are in the resting or telogen phase before shedding. Following a significant physiological trigger, a larger-than-usual number of follicles may shift into the telogen phase. The resulting hair loss is delayed, so shedding often becomes apparent several weeks to a few months after the triggering event rather than immediately.

The questions patients naturally ask are: Will I go bald? Is this serious? Will the hair grow back? In most cases, acute telogen effluvium is temporary and non-scarring, and hair growth gradually recovers once the triggering factor has resolved.

Telogen effluvium and COVID-19

Telogen effluvium is a well-recognised disturbance of the normal hair cycle. It occurs when a physiological or psychological trigger causes an increased number of follicles to enter the telogen phase, leading to diffuse shedding some time later. Potential triggers include acute illness or infection; high fever; major surgery; childbirth; significant psychological or physiological stress; rapid weight loss or nutritional deficiencies; and certain medicines or medical conditions.

Sometimes the trigger is clear, while in other cases several contributing factors may occur at the same time. In people who developed telogen effluvium after COVID-19, the infection itself, fever, systemic inflammation and stress may all have contributed. In the majority of patients with acute telogen effluvium, the condition improves spontaneously and the follicles remain capable of producing new hair. However, the duration and intensity of shedding vary between individuals.

When an underlying cause can be identified and treated, correcting it can help support recovery. It is also important to explain that there is usually a delay between the triggering event and visible hair shedding.

If the problem does not improve as expected, medical assessment can help confirm the diagnosis and rule out other causes of hair loss. Evaluation may include a detailed medical history; examination of the scalp and hair; digital trichoscopy; a pull test; and blood tests where clinically indicated.

Laboratory investigations may include thyroid function, iron status and other parameters depending on the patient’s history and clinical findings.

Advice for telogen effluvium after COVID-19

The following recommendations may help if you experience increased hair shedding after COVID-19.

Do not assume that you will lose all your hair

Acute telogen effluvium is usually temporary. Shedding may be very noticeable, but complete loss of scalp hair is not typical. In many cases, the increased shedding lasts for several months and is followed by gradual regrowth. The exact timescale varies, so recovery should not be expected to follow the same pattern in every patient. Many cases do not require specific treatment beyond identifying and correcting any underlying trigger where possible and allowing the hair cycle to recover.

Wash and brush your hair as usual

It is generally advisable to maintain normal hair washing and grooming habits. Washing or brushing does not cause telogen effluvium. It simply removes hairs that had already entered the shedding phase and were going to fall out. Reducing washing frequency therefore does not stop the underlying process. Use gentle hair-care practices and avoid unnecessary pulling, traction or aggressive treatments while shedding is particularly noticeable.

Hair loss after COVID-19: when to seek medical advice

If shedding persists for longer than expected, becomes progressively worse or causes particular concern, it is advisable to consult a specialist in telogen effluvium. A medical assessment can help confirm whether the hair loss is consistent with telogen effluvium; identify possible persistent or additional triggers; rule out other forms of alopecia, including androgenetic alopecia; and determine whether treatment is appropriate.

In some cases, a dermatologist may consider treatments aimed at supporting hair growth, depending on the diagnosis and the patient’s circumstances. Nutritional supplements should not be taken routinely without evidence of a deficiency or another clear indication. Many supplements marketed for hair loss have limited evidence of benefit, so their use should be discussed with a dermatologist expert in hair disorders.

We invite you to share this article about hair loss after COVID-19 with family and friends who may find it useful.