White Spots on the Skin: The Most Common Causes
December 12, 2025Subungual Hematoma
December 12, 2025Hair loss is one of the most common aesthetic disorders among adults. It is estimated that two out of three men experience some form of hair loss by the age of 35, while the same occurs in more than one in ten women.
Hair consists of layers of dead cells held together with connective tissue and a little water. Precisely because it is not living tissue, we do not feel pain when cutting it. The average adult has 100,000 to 150,000 hairs on the scalp, losing up to 100 daily. At any given time, 90% of our hair is in the growth phase.
Each hair grows from a follicle, which has its own life cycle. Follicles are influenced by many factors, and their condition determines how long we will have our hair, how long it grows, and when (and if) it falls out (temporarily or permanently).
“Hair loss has many causes, which also determine its type—whether it will be gradual or sudden, whether hair will thin or patch in certain areas, whether it will be temporary and regrow on its own, or whether it will require treatment,” says dermatologist-venereologist Dr. Markos Michelakis, from EDOEAP. “Causes may be innate or acquired and include conditions beyond our control as well as issues we can manage.”
Among these conditions, the most well-known are genetics and stress. Genes inherited from both parents can influence our predisposition to developing primarily androgenetic (male-pattern) alopecia, which is the classic hair loss with permanent hair loss observed in men and women. Similarly, stress can lead to temporary hair loss or, more rarely, trigger autoimmune disorders that affect the scalp.
Hormonal changes that occur naturally or due to disease can also affect our hair. Pregnancy, childbirth, and menopause fall into this category. The same applies to thyroid diseases and polycystic ovary syndrome, the most common endocrine disorder in women of reproductive age.
Specifically, childbirth can affect hair due to the intense stress it causes in the body. Generally, highly stressful events may leave their “mark” on the scalp, but their effect is usually temporary. Hair loss can be observed for several months after childbirth, a serious illness, surgery, divorce, or the loss of a loved one. When hair loss is caused by a highly stressful event, it usually takes 6–9 months for hair to regain its previous density, explains Dr. Michelakis.
The use of certain medications can also cause hair loss. A classic example is chemotherapy for cancer, but other medications may affect hair as well. These include anticoagulants for preventing thrombosis, beta-blockers used for hypertension, and certain contraceptives (which may cause hair loss for a short time after stopping them due to temporary hormonal imbalance). Hair can also be affected by some medications for arthritis, depression, gout, heart disease, etc.
“If you believe your hair loss is due to a side effect of a medication, discuss it with the doctor who prescribed it,” advises Dr. Michelakis. “Do not stop taking them on your own, as some medications can have serious consequences if abruptly discontinued.”
Radiation therapy in the head area for cancer may also lead to scalp hair loss. Hair loss usually begins 2–3 weeks after starting radiation, and typically reverses after treatment. However, new hair is usually not as dense as before, and some patients may develop patches without hair. The more radiation treatments a patient receives, the longer it takes to start regrowing hair.
Hair loss can also result from several medical conditions beyond thyroid disorders mentioned earlier. Other diseases that may cause it include systemic lupus erythematosus, diabetes, iron-deficiency anemia, eating disorders (e.g., anorexia nervosa), anemia, and scalp psoriasis.
In these cases, hair regrows once the underlying medical cause is treated, unless scar tissue forms in the scalp in the meantime. This risk exists with some forms of lupus, lichen planus (a type of autoimmune skin rash), and certain follicular disorders.
Even some sexually transmitted diseases can cause hair loss. Syphilis is one of them. If not properly treated, it can cause patchy “bare” areas on the scalp, eyebrows, beard, and other parts of the body.
Nutrition is also important. Insufficient protein intake and very restrictive diets may cause temporary alopecia. The same applies to deficiencies in biotin, iron, or zinc in the daily diet.
Finally, hair loss can result from improper hair care. Frequent heat styling, repeated coloring, washing with hot water, vigorous towel drying, perms, etc., can weaken hair and make it fragile. Similarly, strong pulling back (e.g., tight ponytails or buns), especially when predisposed, can damage the hair root due to traction. These effects are temporary if the cause is removed. However, if scar tissue develops in the scalp, they become permanent.
“Although many causes of hair loss can be effectively treated, the cause must first be identified in each patient individually. Without an accurate diagnosis, treatments for alopecia may prove ineffective,” concludes Dr. Michelakis.
https://www.se-plasticsurgery.com/blog/hair-loss-affects-over-80-million-americans/
https://www.aad.org/public/diseases/hair-loss/causes/18-causes
https://www.mayoclinic.org/diseases-conditions/hair-loss/symptoms-causes/syc-20372926
https://www.everydayhealth.com/skin-and-beauty-pictures/ten-causes-of-hair-loss.aspx
https://www.webmd.com/skin-problems-and-treatments/hair-loss/understanding-hair-loss-basics
