Is dry, brittle, prone-to-breaking hair due to stress alone? It depends on your definition of stress, and your inclusion of hair care and lifestyle factors. Like any other health condition, researching one's medical history and personal habits can build awareness, inform actions and lead to a more complete picture of health.
Hairs begin underground, so to speak, beneath your scalp. Healthy root bulbs can better anchor and nurture the upper hair follicles. Each hair follicle produces a single hair. Your scalp hosts a veritable forest of follicles, given that an average head has 100,000 hairs, of which some 100 are shed each day. New hairs may grown 1/4" - 1/2" per month, but they only last between two and six years. So even under the most benign circumstances, the health of your tresses is continuously fluctuating. Moreover, nutrition, hormonal balance (i.e., use of hormonal supplements, pregnancy and other life stages) and environmental exposure can all affect the strength and resilience of head hair.
Before pinpointing the causes of hair breakage, we must first explore the factors affecting hair density. The size and quantity of the hair follicles on each head determines overall hair thickness. Heads with more follicles have more hairs, and therefore more dense heads of hair. Larger follicles also produce thicker hairs. Color also complicates the equation. For instance, blonde hair has less pigmentation; the hair shafts are less dense; and so more hairs are needed to cover the scalp. So (natural-born) blondes tend to have more hair than individuals with other hair colors. Yet humans vary widely; when comparing notes between a group of blonde-haired people, the actual number and thickness of hairs could be completely different. That said, blondes tend to have the most hair strands, then brunettes, then redheads.
Hair strands exhibit a range of tactile qualities: straight, curly, wavy and so on. These characteristics can be traced to the shape of the hair follicle. However, hair-care products and procedures (perms, coloring, relaxing etc.) primarily affect the hair shaft, and therefore have a limited lifespan. However, changes in nutrition or lifestyle (or trauma, including chemotherapy) can affect the condition of the follicle. This helps to explain why post-chemotherapy, a patient's new hair may have a completely different color, thickness or texture.
The sebaceous glands on the scalp produce oi,l which helps protect and strengthen the hair. While excess sebum can lead to oily hair, over-washing can also deprive hair of this necessary moisture. However, there are also some ethnic considerations for hair elasticity and moisture. While African hair contains more sebum, the oil does not distribute evenly, due to the densely curled hair fibers. As a result, African hair may be more prone to hair breakage. In general, curly hair tends to be more coarse and less soft than straight hair. Yet lifestyle remains an important factor, in terms of hair health.
While everyone wants to look good, it is possible to be overzealous. Hair breakage can result from overexposure to intense heat or friction (combing) of wet hair, chemical treatments, tight hairstyles (such as ponytails or braids) and vigilant brushing. Any or all of these actions can damage the hair cuticle's outer layer. With less protective coating, the inner layer of hair is exposed. The hair appears more dull, dry and static-prone, which may wrongly inspire more products and handling. Similarly, emotional and psychological stress may trigger more fervent hair treatments with less clear perceptions of ramifications.
Stress and Health
While frequently blamed for hair loss, stress can be healthy. Perceiving danger can infuse stress hormones into the body, shutting down your digestive and immune systems while elevating your heart rate and blood pressure. You are abruptly prepared to expound heroic amounts of energy, but unfortunately, it is not always warranted. Moreover, the recovery from this "flight or fight" state requires still more energy, diverting additional resources from your equally crucial "rest and digest" stage. Repeated (perceived) red-alerts lead the body into a state of jet lag, where it is unable to process events and situations clearly and respond appropriately. Nourishment, growth and regeneration may be shunted for seemingly larger crises. Overall health can decline, resulting in brittle hair, which breaks all too easily.
Hair as a Medical Alert
In some cases, hair breakage may be due to medications, hormonal changes (pregnancy or birth control medications) or it may indicate the onset of a medical illness (such as diabetes or thyroid complications). Prior to contacting a health-care provider, individuals should attempt to reconstruct their hair history. The onset, duration, location and quantity of hair breakage are distinct yet related facts that can help diagnose and treat internal health -are conditions that may be manifesting in the hair (among other places). While consumer products abound, one should consider one's hair carefully and respectfully as a marker and extension of internal health.