I'm a guy, but while I didn't notice like, super duper abnormal hair loss, I'd lose a few strands here and there, seemingly like everyone else.
One thing I did, though, switched to not using shampoo, and just rinsing my hair under water in the shower. Occasionally, I'll clean it with some lemon juice like every few weeks, and the acids in the lemon juice straighten out the scales on your hair, so it feels and looks smooth, and it helps get rid of some excess oil, too.
However, if you're willing to take the dare of no shampoo on, what'll happen is for a few weeks, your hair will be nasty. Just oily nasty hair. Then, it'll start looking and feeling better, and eventually you'll get to a point of your hair being awesome, better than it ever was with shampoo and conditioner. The reason this happens is, when you use shampoo, you strip off ALL the oil off your hair, and your body feels this and is like "why's there no oil?" and just makes more to compensate for no oil being there.
The logic of shampoo and conditioner if you think about it really makes no sense, you strip off the oils on your head with shampoo, then put more oil back on with conditioner? So no shampoo breaks the cycle and allows your body to return back to normal.
I can understand people's apprehension to this, especially a woman. Women, especially, if they try this, it's much harder, as they got more hair, so the "break in" takes much longer, instead of like 2 weeks, it could take months. Also, women are judged based on their hair's look, and guys not so much, so if it turns out to be, well, crazytalk, then you got more to lose than some random 20 year old guy.
What you can do, if you don't wanna take the plunge, is just use less shampoo, don't wash your hair everyday, maybe switch to every 3 days, or just use less shampoo when you wash your hair.
I can't account for any biological stuff besides that, stress, different nutrition, diseases, whatever, so if those are a factor, then yeah, try to fix those. But personally, I remember before when I was using shampoo, I'd lose more strands of hair just running my fingers through my hair than I do now, your hair grows faster, too, your body needs the oil for your hair to grow. The other thing it does, too, it gives your hair lots of body, if you like that. Apparently on guys people think that's weird, but whatever, their problem. If you're interested, just google no shampoo or no poo, and you'll see other people's stories and methods and can decide for yourself whether you want to do it.