Your hair could be thicker

All forms of tension can cause your hair to thin. A simple bun, ponytail, and or braids.
Curly hair follicles are curved not straight. What does this mean? Curly hair grows in all directions, verses straight hair grows in one direction. When we pull our hair in one direction this causes tension. Even this tension will thin your hair. If you wore moisturized styles that allow your roots to flow and be puffy, you would notice your hair get much thicker.