You’ve got hair — but have you ever stopped to think about how it actually grows? What causes our hair to squeeze out of our scalps like a Play-Doh spaghetti maker? Today, we’re going to take a look at the ins and outs of the hair growth cycle to learn more!
Where Does Hair Come From?
Hair grows out of the root — called a follicle — just underneath the surface of the scalp. The follicle consists of two parts: the bulb and the papilla. The former holds all the cells that cause growth and the latter supplies the blood to keep it all healthy. As the hair cells rapidly divide, the shaft forms and grows out of the follicle — that’s the strand we think of when we see the word hair! Eventually, the hair separates from the papilla and will fall out so new hair can grow in its place. This happens in four stages — let’s take a deeper look at them now!
Stage 1 – The Anagen Phase
This is the period where your hair grows! The cells down in the bulb are doing their thing, dividing rapidly, while the papilla provides the necessary nutrition to keep that process rolling along smoothly. This lasts anywhere between 2 and 7 years and during this time hair can grow to an average of 18-30 inches long, depending on genetics and other factors.
Stage 2 – The Catagen Phase
This period only lasts about 2-3 weeks on average and is the point at which the bulb and papilla detach from the shaft. Without the proper blood supply to deliver nutrients and oxygen necessary for growth, the strand dies. No more growth can occur for this particular strand — it’s on it’s way out!
Stage 3 – The Telogen Phase
This is where the dead hair strand gets to Rest in Peace for a little while! After detaching from the papilla, the shaft sits in the scalp while new hair begins to grow in the bulb below. This process takes about 3 months.
Stage 4 – The Exogen Phase
Now the strand takes its final bow and exits the scalp, stage left. The new hair in the bulb below will begin to push out of the scalp and will loosen the previous hair. Once loose, it will either fall away naturally or be brushed out when you comb your hair. The average person loses between 50 and 150 hairs a day during this phase! Wow.
That’s the hair growth cycle! How long does your hair grow usually? Does it take 2 years or is it closer to 7? Ever count the hairs you lose in a day? We want to know! Tell us in the comments!