Hair loss can also be brought on by hormonal changes, which are frequently associated with pregnancy, menopause, thyroid diseases, and conditions like polycystic ovary syndrome (PCOS). Thinning may be exacerbated by several drugs, particularly those that include hair loss as a side effect. Stress, whether it be physical or emotional, can cause telogen effluvium, which causes temporary hair loss. Hair can become fragile and damaged, leading to thinning, as a result of poor nutrition, harsh hair treatments, tight haircuts, and excessive heat styling.