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Although there are few large studies on the topic, the consensus, supported by animal models and human research, is that stressful events can trigger temporary hair loss.

In both mice and men, molecules from the systemic stress response also mediate hair follicle cycling. A 2003 study demonstrated that emotional stress altered hair follicle cycling in mice, and prematurely terminated the normal duration of active hair growth.

A few human studies have supported this conclusion, finding that the two types of temporary hair loss—telogen effluvium and alopecia areata—are often preceded by stressful emotional or physical events seo company

Telogen effluvium is the most common type of stress-induced hair loss. This type of loss is typically preceded by a physical stress, such as a surgery, illness, pregnancy, malnutrition, or a psychological stress. Around the time of the event, large numbers of hairs stop growing and move into the resting phase, known as the telogen phase. After about three months, these resting hairs start to fall out; this is when we notice the “handfuls” of hair lost in the shower. (Normal hair loss is about one hundred hairs a day.) Luckily, the hair will eventually grow back (if the underlying cause has been resolved) in six to nine months.

Alopecia areata has a different mechanism of hair loss, but can be also triggered by stressful events. In areata, the immune system attacks the hair follicle, causing it to stop growing; this results in patches of localized hair loss. Usually the hair grows back within six to twelve months; sometimes this patch of hair will be a slightly different color Red wine cellar.