Why it happens

Hair shedding after dengue, fever or surgery

If your hair started coming out in handfuls a couple of months after being seriously unwell, you are not losing your hair permanently. You are almost certainly seeing telogen effluvium, and the timing is the clue.

What is actually happening

At any moment most of your hair is growing and a small share is resting before it falls. A shock to the body — a high fever, dengue, a severe infection, surgery under general anaesthetic, childbirth, rapid weight loss, a period of real stress — can push a much larger share of your hair into the resting phase at once.

Resting hair does not fall immediately. It sits for roughly two to three months and then releases, which is why the shedding starts long after you feel better and why almost nobody connects the two. It looks alarming because the hair leaves together rather than a few at a time.

How long it lasts

The shedding phase usually runs six to twelve weeks, then stops. Regrowth begins underneath while you are still shedding, so short new hairs along the hairline are a good sign rather than breakage. Getting back to your old density typically takes six to twelve months, because the new hair has to grow the full length again.

What helps, honestly

Nothing shortens it dramatically. What supports it: eating properly again after the illness, correcting an iron or thyroid problem if a doctor finds one, and treating the scalp gently — no tight ponytails, no aggressive brushing while wet, no chemical services during the heavy shedding weeks.

Be sceptical of anything sold to you as a cure during this window. The hair was going to come back anyway, which makes it easy for any product used in month four to take the credit.

When it is something else

Speak to a doctor if the shedding is still heavy after about six months, if it comes out in round smooth patches rather than evenly all over, if your scalp is itchy, scaly, sore or visibly inflamed, or if you also feel exhausted, cold or unwell. Those point somewhere other than a post-illness shed.

Persistent thinning at the parting or the temples that does not recover is a different pattern again, and worth reading about separately.