With age, the hair follicle produces an enzyme named 5 alpha reductase. When the testosterone present in the follicle combines with this enzyme, it produces dihydrotesterone (DHT). Hair follicle receptors are sensitive to DHT and thereby start the process of male or female pattern hair loss.
At any one time, about 90% of the hair on a person’s scalp is growing. Each follicle has its own life cycle that can be influenced by age, disease, and a wide variety of other factors. This life cycle is divided into three phases:
Anagen—active hair growth. Lasts between two to six years.
Catagen—transitional. Lasts two to three weeks.
Telogen—resting phase. At the end of the resting phase (two to three months), the hair is shed and a new hair replaces it and the growing cycle starts again.
As people age, their rate of hair growth slows. More and more hair follicles go into a telogen, or resting, phase, and the remaining hairs become shorter and fewer in numbers.
Androgenic alopecia: one form of hair los, is a genetically predisposed condition can affect both men and women. Men with this condition can begin suffering hair loss as early as their teens or early 20s, while most women do not experience noticeable thinning until their 40s or later.
In men, it is characterized by a receding hairline and gradual disappearance of hair from the crown.
In women, androgenic alopecia is referred to as female pattern baldness. Women with the condition experience a general thinning over the entire scalp, with the most extensive hair loss at the bang and crown. In fact, a woman has to lose about one-half of her hair volume before it becomes noticeable.
Doctors do not know why certain hair follicles are programmed to have a shorter growth period than others. Although a person’s level of androgens—male hormones normally produced by both men and women—is believed to be a factor, hair loss has nothing to do with virility.
An individual’s genes, however—from both male and female parents—unquestionably influence that person’s predisposition to male or female pattern baldness.
Telogen effluvium is temporary hair loss that can occur within a few months after a high fever, a severe illness or extreme stress, and in women following childbirth.
Drugs that can cause temporary hair loss include chemotherapeutic agents used in cancer treatment, Anti-Depressants, Anticoagulants, Retinoids used to treat acne and skin problems, cardiac medications used to control blood pressure, and oral contraceptives.
Although too-frequent washing, permanent waves, bleaching, and dyeing hair do NOT cause baldness, they can contribute to overall thinning by making hair weak and brittle. Tight braiding and using rollers or hot curlers can damage and break hair, and running hair picks through tight curls can scar hair follicles. In most instances, hair grows back normally if the source of stress is removed, but severe damage to the hair or scalp sometimes causes permanent bald patches.
Thyroid and Seasonal Hair loss
One of the major contributing factors to hair loss is hormonal imbalance, which is often attributed to hypothyroidism. The increased production of androgenic hormones, which is one side effect of hypothyroidism, can often lead to baldness in women. Androgens, which consist of the two related hormones testosterone and DHT, cause hair follicles to die and fall out.
Medicine used to treat hypothyroidism can also cause hair loss. The intention of thyroid medicine is to correct a hormonal imbalance; however, because it is yet another factor that alters hormone levels, it can be another cause of hair loss.
Seasonal Hair Loss
Believe it or not, one of the most common causes of hair loss in women is the change of seasons. Though this might seem like too simple of a solution, the changing of seasons has been known to cause hair loss in women. During times of increased temperature, women with thick hair frequently shed some of their locks. It’s similar to when your pet sheds their fur—nothing to worry about at all!
Ruling Out The Worst
Despite thyroid and seasonal hair loss being most common in women, it is important to rule out other, more serious medical conditions that could also be the cause of hair loss. Your doctor can help you to determine whether thyroid and seasonal hair loss is, in fact, your problem—or if the cause could be something more serious.
There are several serious medical conditions that have hair loss as one of the side effects. The conditions could have tragic results if they are not recognized and treated as soon as possible, which is why you should consult your doctor if you experience hair loss.
Some of the more serious medical conditions that could lead to hair loss in women include anemia, ovarian tumors, Lupus, and anorexia. Experiencing hair loss could be a sign of one of these conditions, so make sure to consult your doctor.
No Concerns About These Causes
As far as hair loss goes, thyroid and seasonal hair loss are really nothing to be worried about. While seasonal hair loss must be waited out, thyroid disorders can be treated with medication. Thyroid or seasonal hair loss is easy enough to address.