You were born with really good hair but now you have really bad hair sometimes it gets better but you want to know what can cause this change could it be stress?

Hair is actually not alive, so when we talk about "healthy" hair it means more that the hair looks "good."

Hair "health" can be encouraged by getting enough sleep, drinking plenty of water, good diet, and good--but not excessive--hygiene and grooming. Mild cleansers and shampoos appropriate for your hair type are best; avoid dyeing/perming hair as well.

Stress can certainly change hair, as can puberty, diet, and other diseases.