I use to have that problem but I figured out mine was from not moisturising enough, i'd constantly find hairs on my tops - it became normal
Since I changed my regimen I lose on average 50 (max) hairs a week ... yerp, a week, I get an inch of growth every 2 weeks now...anyway,
If your hair is thin it'll be weaker so it'll shed a lot more, try biotin for thickening it.
ACV (Apple Cider Vinegar) rinses, restore your hairs Ph balance and acidity and level your hairs porosity so it'll hold moisture better (I use to have to moisturise my hair about 3/4 times a day, now once a day or every other day is enough)
A black tea rinse tends to stop or reduce breakage for about a week, so weekly black tea rinses should help.
For moisture, incorporate baggying/Green house effect to your regimen to do overnight (I do it 3 times a week)
I don't know if you want to know my regimen but it's basically extreme protective styling and I only touch my hair on wash days really. I wear wigs the rest of the time but keep my hair moisturised throughout.
Hope this helps =]