When you brush and comb your hair do you look with horror at the number of hairs that fall out and wonder if everything's quite all right? The fact is that unless there's a sudden change in how much hair is left in the brush, there's probably nothing to worry about. Hairs fall out constantly as part of a natural process of renovation.
Experts tell us that there are between 100,000 and 150,000 hair follicles on the scalp, and that at any one time, about 90% of our hair is in the active growth phase. During this phase, the hairs grow about 1 centimetre a month. Some 10% of the hair is in a non-active 'resting' phase that lasts about 3 months. Of the hairs in the resting phase, around 1% fall out daily, which gives us a hair-loss figure of around 100 hairs per day.
Of course when you wash you hair, or when you brush and comb it, rough handling may encourage the hairs in the resting phase to fall before they might have done naturally. It's even possible for your hair style to aggravate hair loss. This means that the number of hairs left on your pillow each morning is actually a much more accurate indication of whether your hair loss is 'normal' than the mat of hairs you clear from the drain after washing your hair in the shower.
Another thing to remember is that these figures are simply averages. Hair growth patterns are largely governed by genetic factors and as long as your hair is renewing itself, there's nothing to worry about: paying attention to changes in hair loss is more important than trying to estimate actual figures, and it's time to consult an expert when your hair loss pattern alters.