There are many things that can lead to thinning hair and hair loss. A very common condition is called androgenetic alopecia, which is also known as male or female pattern hair loss. Genetics play a big factor, as can scarring, and reactions to medication. Not every cause is immediately obvious. For example, some might be surprised to learn that there’s a connection between stress and thinning hair. You also might not know that there is a connection between eating healthy food and having healthy hair.