Many women have thinning hair as they age, and it is caused by the same process that results in thinning hair for men...changing hormones. The treatment is much the same also. I suggest talking to your provider. There are treatments for this, including minoxidil that has been shown to restore and increase hair growth.
However there can be other causes of thinning hair in women that are more medical in origin. A thyroid imbalance (generally too much thyroid hormone) can cause thinning hair, as can a condition called Polycystic Ovarian Syndrome. Liver and kidney problems can also show themselves as thinning hair. IF you have NO other symptoms of ANYTHING else, it may be just age related.
Here is a weblink about thinning hair in women: http://www.aocd.org/skin/dermatologic_diseases/female_pattern_hai.html
To rule out medical causes, I suggest a physician evaluation. He/she can also help you with options if it is age related hair loss.
I hope I was able to help you,
I wish you the best in this.
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