Excessive hair growth can be identified by many different terms. You have probably run across the term Hirsutism, perhaps Hypertrichosis, and even superfluous hair. In many resources these terms are used interchangeably but there are important distinctions.

Excessive hair (key word here is excessive) on the face, especially around the chin, upper lip, breasts or chests, or basically hair on a woman that matches a male hair pattern on a female body is known as hirsutism. Men can have hirsutism when their hair is truly excessive in hormonally dependent areas. A diabetic woman with a full male pattern beard would be said to have hirsutism.

Hypertrichosis is basically excessive hair on men or women that tends to be in places that are outside the pattern areas described above. Someone who has a cast on their leg who grows unusually large patches of hair under the cast could be said to have Hypertrichosis (hyper=excessive/accelerated trich=hair).

Superfluous hair or garden variety “unwanted hair” is considered such whenever it appears on areas of the body that are considered to be either culturally unacceptable, or unattractive. It isn't an abnormal amount or location when considering the makeup of the whole population; it is just undesirable for a woman to have a noticeable light mustache. The color of the unwanted hair is also key; the darker it is, the more visible—which makes it more of a problem for dark haired women than for fair haired women. If you are dark haired, for example, the fine hair on the upper lip or around the hairline may feel abnormal but it’s not; it’s merely visible. And even though excessive hair growth on the face or male-patterned hair growth on the body is considered “abnormal” in women, it’s actually very, very common.