
Stress

After aging, stress is the main reason for thinning or excessive hair loss. Scientists aren't quite sure, but they think it is because stress is linked to low vitamin B levels and hair needs lots of B vitamins to maintain strength and condition.
If your hair has begun to fall out more, or is weaker and thinner, then it might be time to take action and increase your well-being. Consider participating in activities that help you relax - such as joining a gym, learning to meditate, buying a pet or spending more time outdoors. Any activity that can decrease stress, improve your overall health and help you regenerate healthy hair will benefit you!
Hormones
The body's testosterone levels are linked to hair loss and baldness in both men and women. Testosterone can be converted to dihydrotestosterone (DHT) in the body and this hormone shrinks hair follicles and restricts blood flow in the scalp. When hairs fall out, they aren't replaced.
This is why so many men lose their hair in middle age.
Drops in oestrogen can also thin a woman's hair. This can happen if you have recently changed or stopped using the contraceptive pill, become pregnant, had a child, commenced or finished HRT, or are going through menopause.
Taking the contraceptive pill can sometimes lead to an increase in hair health.
Poor nutrition
Dieting and poor nutrition can be to blame. If you have been on a diet you may have limited your food choices and missed out on vital vitamins and minerals. Specific foods or vitamins won't re-grow your hair but good nutrition is vital for thick, strong hair. Take a multivitamin every day.
Anaemia (low iron levels) can also lead to thin, weak hair. Have your blood's iron levels checked by your GP and eat an iron rich diet.