This is the loss of hair due to sensitivity of the hair follicles to androgens over time. It is also called male or female pattern baldness. Women produce androgens, much lower than men, but do so just the same. As estrogen levels wane with age, the ratio between estrogens and androgens changes so that the hair follicles ”see” more androgens, causing hair loss. In men the androgen surge through puberty causes “excess” androgens to the hair follicles, also causing hair loss. In both cases there may be a variability in when the loss is noticed, and to what degree. That is what is inherited, and the inheritance can come from either side of the family, or be a new mutation. There is no diagnostic test for this, as the diagnosis is made by history and exam of the hair loss “pattern”. A scalp biopsy is sometimes performed, but is more helpful in other types of hair loss. The pattern is usually frontal in both men and women, and/or occipital in men. While there are several different patterns seen, it is important to remember that women almost never have the same degree of loss as men do. Once diagnosed, what can be done? Unfortunately there is no magic potion or pill to grow hair. There are some things that can help. Any multivitamin with zinc will help hair (and nails) to grow. The level of zinc in the vitamin is all that is needed. The other supplement is biotin, which you will need to take 2500 micrograms, or 2.5 milligrams daily. Less than that will not be effective. Minoxidil (Rogaine) foam, extra strength (brand or generic) at least once daily will also help, at least to maintain the current hair density. These things will also make the hair diameter thicker, appearing to have more hair. Most studies demonstrate a 20% improvement, depending upon the duration of hair loss(earlier the better) prior to starting. A word about stopping minoxidil. Once stopped, you will slowly lose the hair ( over 12-24 months) that you would have lost if you did not use minoxidil, no morehair loss than that. One can also use light therapy to stimulate hair growth-in office procedures, or by purchasing a Hair Max(or equivalent) “comb”. This is about half as effective as minoxidil use. Spironolactone is a mild diuretic tablet that is an anti-androgenic agent, used sometimes in women of non-child bearing age. Men cannot use it as it is considered a “feminizing” agent. Men can use finasteride tablets instead(women cannot unless unable to get pregnant). As with any systemic agent there can be side effects and some degree of monitoring is required. As to the degree of success, it is variable, and should be some improvement with consistent use (can take up to 24 months to see a change), at the very least should keep things from getting worse. Nothing else has data to suggest an increase in the number of hairs grown. Some conditioners can thicken the hair, which gives an appearance of more hair. One should avoid using the hot setting on hair dryers as well. The amount and type of shampoo used is irrelevant, as are permanents, and hair coloring.
There are other causes of hair loss. These usually cause more diffuse loss, instead of patterned. There are tests to diagnose these causes, and treatment available. They are usually divided into scarring(ie:lupus), and non-scarring(ie:anemia,thyroid, medications). A relatively new entity is seen primarily in women over 50 taking blood pressure (and other) medications. Another patterned type of hair loss that is seen commonly is the condition called alopecia areata(hair loss in an area). It is seen in all ages, with one or more completely bald areas of hair loss. The cause is unknown, but is an auto immune phenomenon as the patient’s immune system is causing the hair to stop growing. Stress is felt to be the number one cause, and the condition usually resolves without treatment, but the hair may come back grey or white. Treatments are effective in this condition, depending upon the age of the patient. There can be significant loss of hair, sometimes all hair is lost. Fortunately these latter scenarios are very rare. There is also a common cause of generalized hair loss due to stress- most commonly seen post delivery in women(and any other stress full life event). Called telogen effluvium, it is a global thinning of scalp hair( thinning as opposed to bald spots seen in alopecia areata), and occurs 6-12 months after the event, and usually resolves over time, but my require therapy.
For hair loss of the eyelashes and eyebrows, latisse has a very good track record for improving the hair loss. I have also used it for small areas of scalp loss as well. Unfortunately the scalp response to date does not mirror the success of eyelash/eyebrow therapy.
When you notice hair loss, it is important to try to determine if there is a treatable cause first, which is accomplished with blood tests and sometimes a biopsy. The results of these tests will guide therapy, which is usually most effective when there is a specific diagnosis(ie anemia).