Can a scalp biopsy tell what kind of hair loss you have? Is it genetic or telogen effluvium? (Photo)

It does not replace a good physical examination, but if a doctor is uncertain about the cause of your hair loss he/she may obtain a biopsy for more insight to the root of the problem.

genetic alopecia is the most common reason of hair loss in women and men  and it is more common than it is thought to be. 25% of the women at the ages of 35-40, 50% of the women and men at the ages above 40 suffer from hair loss. Other reasons of hair loss are: Hypo- and hyper-tiroidism (hair loss may be one of the early signs of thyroid dysfunction, and hair loss stops after treatment); polycystic ovarian syndrome (an inherited ovarian disease, seen in 10% of the women during adulthood); pregnancy-related hormonal changes (temporary hair loss which can be seen during pregnancy stops after birth)..

The reason of the hair loss may related with factors other than genetic like connective tissue disorders, stress, anemia, lupus, medications, hormonal and seasonal changes, nutritional problems, severe diets, bulimia, protein/calorie deficiency, zinc and essential amino-acid deficiency, mal-absorption (intestinal and digestive problems), A-vitamin excess, general anesthesia, affective mood disorders.

Drugs that may cause hair loss in woman 

Anti-coagulants such as warfarin and heparin  
Epilepsy drugs, especially dilantin
Gout drugs, allopurinol and colchicum
Antihypertensive drugs, diuretics, beta blockers.... etc
So you may need dermatoscopy and ıf needed a skin biopsy and to have a full exam with an hair surgeon and/or endocrinologist , to find out any reason for hair loss.