What condition can be characterized by hair loss or thinning?

Alopecia is the term used to describe hair loss or thinning. This condition can manifest in various forms, such as alopecia areata (a sudden loss of hair in patches) or androgenetic alopecia (commonly known as male or female pattern baldness). It can be caused by genetic factors, autoimmune responses, hormonal changes, or environmental influences.

Those experiencing alopecia may notice significant patches of hair loss or overall thinning of hair on the scalp or other areas of the body. This condition is distinct in that it directly affects hair follicles, leading to a decrease in hair density or outright loss, making it a primary concern for individuals affected by it.

In contrast, while conditions like trichotillomania involve hair loss, they stem from behavioral compulsion to pull one's own hair rather than a physiological condition that affects hair follicles directly. Dandruff and seborrheic dermatitis may cause flaking and irritation on the scalp but do not inherently lead to hair loss or thinning.