The average person has about 100,000 to 150,000 hairs on their head. Shedding 30-50 hairs a day is completely normal. When you start seeing 100-150 strands of hair a day, that is when you should think about seeing a doctor or specialist.
The most common causes of hair shedding include heat damage and diet. Heat damage from hair dryers, curling irons and hair straighteners can cause hairs to break and fall out. Diet is also important. If your hair is not getting the vitamins and proteins it needs, your hair follicles will not be strong and healthy.