Did you know that the hairs on your head go through a constant life cycle? While we often think of shedding as a negative, everyone sheds some hairs due to the normal hair life cycle (visible hair loss occurs when there is excessive shedding). There are three phases of the normal hair life cycle: Anagen, Catagen, and Telogen.
- The Anagen phase is also known as the “growth” phase. This is the beginning of the hair life cycle. As the blood supply nourishes the follicle with important nutrients, the hair grows healthy and strong. The Anagen phase can last anywhere from two to six years.
- The Catagen phase is also known as the “transition” phase. During this phase the hair follicle starts to detach from the blood supply. The hair stops growing longer or thicker. The Catagen phase can last anywhere from two to three weeks.
- The Telogen phase is also known as the “resting” phase. This is the last stage of the hair cycle and is when the hair will fall out. While typically, hairs are not all going through the telogen phase at once, it is possible, due to stress or other factors, for an increased number of follicles to be in the telogen phase, causing a significant shedding event. This is known as telogen effluvium. The Telogen phase can last anywhere from three to four months.
Over time, due to genetics, it is possible for the entire hair life cycle to shorten. This means overall your hairs are in the Anagen “growth” phase for less time, causing hairs to miniaturize as they have less time to grow healthy and thick. This miniaturization is what we see with Female Pattern Hair Loss (FPHL). The good news is that with the correct treatment this miniaturization can be halted and potentially reversed.