Hair grows from the follicle or root underneath the skin. The hair is ‘fed’ by blood vessels at the base of the follicle, which gives it the nourishment it needs to grow. Between starting to grow and falling out years later, each hair passes through 4 stages: anagen, catagen, telogen and exogen. Every hair is at a different stage of the growth cycle.
Over time, the length of the anagen stage decreases. Therefore, the hair may become weaker and thinner after each cycle. That is why it is important to ensure your diet is rich in specific nutrients to promote existing hair growth from within.