The most common causes of hair loss in dermatology clinics are stress related or telogen effluvium, and hormonal hair loss otherwise known as androgenetic alopecia.
Stress induced hair loss self settles over the course of a year and a series of multivitamins and scalp tonics can be helpful to accelerate that regrowth.
Hormonal which includes male pattern balding and female pattern balding is progressive (so continues to get worse over time) and treatments are variable. One treatment which is very effective is platelet rich plasma which is extracted safely from your own blood sample and injected into your scalp where there is hair loss. It contains a number of growth factors which promote hair growth. This is a relatively painless procedure and we recommend 2-3 treatments about 4-6 weeks apart. You can expect 60-70% regrowth.