The Hair Growth Cycle
The hair growth cycle is continually revolving around the three phases.
Anagen phase –> Catagen phase –> Telogen phase
The anagen phase– It is also know as the growth phase. The hair grows actively in the hair follicle. It reaches maximum length in 2-6 years.
The catagen phase– It is also known as the transitional phase. The hair stops growing and dies. This phase last around 2-3 weeks.
The telogen phase– Also called the shedding/ resting phase. A new hair then regrows(starting the anlagen phase again) and pushes the old dead hair out of the follicle.
Multiple factors can cause hair loss. Summarized below are the most typical causes hair loss.Hair loss (alopecia) and its exact underlying cause and treatment may be challenging.
1. Hormonal causes:
Androgenetic hair loss is male pattern baldness in men and is caused by levels of dihydrotestosterone on the hair follicles. In women, the pattern of hair loss is different & most often seen in the postmenopausal years. Women do not go completely bald such as men, but gradual hair thinning is common. In both men and women, the cause of androgenetic hair loss is genetic and due to increased levels of male hormones, called androgens. After menopause, there is an increase in male-like hormones leading to female pattern hair loss or thinning.
The medication, Propecia (finasteride) works by blocking the receptors in the hair follicle from testosterone. This medication is FDA approved for men only.
2. The polycystic ovarian syndrome:
It is also is known as P COS is another form androgenic alopecia although it in although occurs in young women. There are various degrees of severity of PCOS, and some women may also be accompanied by acne, insulin resistant, weight gain, and infertility. Onset starts at puberty and a pelvic ultrasound best diagnoses it
After childbirth, women may experience shedding of her hair. This type of hair loss is called telogen effluvium and is caused by multiple hairs simultaneously entering the telogen (shedding) phase. Women notice a dramatic shedding of their hair.
4. Thyroid dysfunction:
The hormones from the endocrine system are intricately interrelated low thyroid can cause hair loss as well is dry and brittle hair. The thyroid is usually evaluated in the workup with hair loss.
5. Diet and nutrition:
Multiple vitamins and minerals can cause or worsen other types of hair loss. Low iron and anemia are known causes of hair loss. The hair vitamins, and the minerals important in the maintenance of healthy here include vitamin A, vitamin C, vitamin D, vitamin E the B vitamins biotin 10 and B12, and the minerals zinc and selenium. Protein deficiency can contribute to hair loss. Heavy metal toxicity including lead, mercury, and cadmium can also contribute or cause hair loss
6. Stress/ Shock:
A telogen effluvium may appear 6 months after severe stress or shock, a death of a family member trauma surgical procedures or car accidents. As mentioned above telogen effluvium is when all hairs enter the Telogen resting phase and shed simultaneously again. Fortunately this type of hair loss is usually reversible within 3 to 6 months.
Multiple medications can cause hair loss or hair thinning. The most common ones are; cholesterol-lowering medications, anti-seizure, hypertensive medications and anticoagulants. This is just to name a few.
Cancer chemotherapy medications are targeted to attack growing cells of the tumor. Many of the chemotherapy agents also effect the growth phase or anagen phase of the hair growth cycle. This occurs within a week of chemotherapy and all of the hairs in the anagen phaselusually is reversible after the chemotherapy is complete medication
8. Autoimmune Disease
There there are a few various autoimmune diseases that can lead to hair loss these include systemic lupus
Alopecia areata is an autoimmune type of hair loss which is usually patchy bald spots on the scalp where are the immune cells it has attacked the hair follicles. Depending on the age of onset this type of hair loss is frequently treatable.
Diagnosis and Evaluation of Hair:
*Laboratories to order will depend on the physical exam and may include the following
- CBC with diff
- Iron Saturation
- Total Iron Binding Capacity
- TSH, T3, T4 (Thyroid hormones)
- Vitamin D level
- Zinc level
Treatment options vary depending on the type of hair loss that is diagnosed based on the results of the above tests and physical exams. Modifying your diet and medication intake (including vitamins), as well as stress, can significantly affect the outcome.