Why your hair is thinning or shedding

A sudden shed can bring years of gradual thinning to your attention. The illness or weight change that triggered the shed may explain the recent loss. The earlier thinning still needs an explanation of its own.

That overlap is common enough to matter at the first assessment. The useful starting point is a record of what changed, where it changed and when. Choosing treatment follows that understanding.

Establish which change is occurring

Thinning, shedding and breakage describe different processes. In pattern hair loss, hairs gradually become finer. During a shedding episode, more hairs leave the scalp. With breakage, the shaft snaps while part of the hair remains. A scalp disorder can also affect the follicle that makes the hair.^1,2

These changes can occur together. A person may need help with inherited thinning, recovery from a recent shed and damage from hair processing. One treatment may address only part of that picture.

The newest change may explain why you noticed the problem, while an earlier process explains part of the loss.

Put the history in order

Shedding can begin months after illness, surgery, childbirth or substantial weight loss. By then, the earlier event may seem unrelated. A timeline helps connect events that are easy to separate in memory.¹

Include changes in prescribed drugs, supplements, weight, eating and hair care. Note starts, stops and dose changes. Medicines used for other health conditions matter as much as products sold for hair.

Cancer treatment illustrates the importance of that detail. Some treatments disrupt active growth. Endocrine treatment for breast cancer can cause gradual thinning resembling pattern hair loss. The medication name and the type of hair change both matter.³

Examine the hair and the scalp

A wider part, a receding edge and a patch of short hairs need different observations. Looking closely at the shaft helps separate finer hairs from fractured ones. Examining the scalp adds information about inflammation and possible damage to follicles.

Pain, scale, burning or sores belong in the history. The amount of discomfort alone cannot establish which condition is present. Older photographs can show whether the area was changing before symptoms began.

Give each contributor a place in the plan

Nutrition, thyroid disease and other health changes deserve investigation when the findings support it. Recent restriction, digestive problems and difficulty eating are useful details at any body size. Menopause and aging provide context; the scalp findings still need to fit the explanation.

Before an assessment, write down the sequence and gather previous reports and treatment details. I use the history and examination to identify the causes requiring attention, recommend what to address first and define any investigation still needed.