The best way to think of the way hair grows is to picture a garden. How well it grows is completely a result of what is happening “underground.”

“Like a garden,a normal hair cycle should lead to a product, which is the hair,” says Wendy Roberts, MD, a dermatologist at a private practice in Rancho Mirage, Calif. “Growth cycles are important because when they go awry, that is one of the reasons we have hair loss.”

And things that interfere with the cycle -- like medication, illness, infection, or chemicals -- have the potential to stop hair from being formed properly.
​
"It’s a very dynamic place and anything that can get the cycle off can cause hair loss,” Roberts says.
​
Although hair loss may seem like a more prominent problem in men, women are nearly as likely to lose, or have thinning, hair. Most women notice it in their 50s or 60s, but it can happen at any age and for a variety of reasons.

Way to Grow
Hair grows in three different cycles: anagen, catagen, and telogen. About 90% of the hair on the head is in the anagen, or growth phase, which lasts anywhere from two to eight years. The catagen, or transition phase, typically lasts 2-3 weeks, during which the hair follicle shrinks. During the telogen cycle, which lasts around two to four months, the hair rests.
An overwhelming majority of the time the hair is on the scalp, it is growing. Only about 10% of the strands are in transition or resting at any one time. Hair grows about 6 inches a year for most people.
​
At a Loss
Most people lose anywhere from 50 to 100 strands of hair each day, according to the American Academy of Dermatology. On the days when hair is washed, people can lose up to 250 strands, Roberts said. But don’t avoid washing in an attempt to keep the hair, as it will fall out eventually, anyway.

For those who don’t plan on counting their hair every day, there are ways to know when hair is thinning or being lost at a higher rate. Roberts tells WebMD that women will see a difference. When waking up in the morning, there may be an usually large amount on your pillow. When you comb your hair (especially without tugging, which can pull the hair out), more than normal will be left in the comb.

There are also other visual cues that women can look for over time. Although men’s hair tends to recede from the forehead or the crown of the head, women tend to notice thinning on the top third to one half of the scalp. Sometimes their frontal line stays intact, says Nicole Rogers, MD, of Old Metairie Dermatology in Metairie, La. Women may see a part that is gradually becoming wider or see more of their scalp than normal when their hair is pulled back.
​
When a patient comes in with concerns about hair loss, there is a combination of ways to make a diagnosis, Rogers says. Preliminary blood work is usually taken to make sure the thyroid gland or an autoimmune disease isn’t the culprit.
​
In Your GenesAnother way to diagnose what the problem is just by looking and listening, Rogers says. She asks what a patient’s mother, aunts, or grandmothers look like - if they have similar, or greater amounts, of hair loss. Using magnification on the scalp can show if a woman’s follicles vary in size - with some thick and others thin. These are two telltale signs of female pattern hair loss, also called androgenetic alopecia.

This is a hereditary condition that affects about 30 million American women, according to the America Academy of Dermatology, and is the most common kind of hair loss Rogers sees in her practice. She tells WebMD that it happens to about 50% of women. Although it mostly occurs in the late 50s or 60s, it can happen at any time, even during teenage years, Rogers says.

Typically, each time a normal hair follicle is shed, it is replaced by hair that is equal in size. But in women with female-pattern hair loss, the new hair is finer and thinner - a more miniaturized version of itself, Rogers says. The hair follicles are shrinking and eventually they quit growing altogether.

Medical and Other ConditionsIf hair follicles are uniform in size, or if the hair loss is sudden, it is likely to be caused by something other than heredity, like a medical condition, Rogers says.

​
​There are a wide range of conditions that can bring on hair loss, with some of the most common being pregnancy, thyroid disorders, and anemia. Others include autoimmune diseases, polycystic ovary syndrome (PCOS), and skin conditions such as psoriasis and seborrheic dermatitis, Rogers says.

Though there has been a link between menopause and hair loss, Roberts says she doesn’t think there is a direct correlation. It could be that menopause and hair loss just occur at the same age.

Other reasons for hair loss include extreme stress; physical trauma like surgery or intense illness; dramatic weight loss over a short period of time; and taking too much Vitamin A, Roberts says. And hair loss can occur a couple of weeks to six months after any of these experiences.

“Someone can have surgery and be just fine and then two weeks later their hair starts falling out,” Roberts says. “It can be very scary when it starts falling out in big clumps.”

Easy Does ItOne other way to thin hair is self-inflicted - hairstyles like cornrows or too-tight braids can cause hair loss called traction alopecia.

All of the things women do to manipulate their hair -- dyes, chemical treatments, bad brushes, blow dryers, and flat irons -- can result in damage and breakage, Roberts says. This includes brushing too much and towel drying aggressively when the hair is wet.
​
Luckily, for most of these issues, the hair grows back or the loss can be reversed with medical treatments. But it is important to see a dermatologist if there seems to be something wrong, because the sooner treatment is started, the better the chances are for improving your growing season.

WebMD Feature Reviewed by Brunilda Nazario, MD on June 11, 2012

We know that many of you struggle with having to wash your hair every day because the grease is unbearable (here are 14 eternal struggles, to be specific), but getting to the root of the problem – quite literally – makes more sense than battling the beauty affliction. So here are 8 things to stop doing that could be the cause of your greasy hair.
1. Touching your hair too oftenMORE FROM HAIR

15 super-gorgeous pastel dye jobs

Zendaya's secret to getting super healthy curls

This is why your hair goes grey...Like constantly touching your face (which is a whole other beauty blunder in itself) fiddling with your hair – flirtatiously or out of boredom – transfers oils from your fingertips to your strands. Also try and (nicely) discourage your boyfriend from touching your hair too much in bed – feels nice but doesn't look nice come morning.

2. Over-washingYes, you wash it to cleanse the grease, but no, it doesn't help. Unfortunately daily shampooing can strip your scalp of its natural oils – so it produces more in a bid to replace them. Try cutting back on washing your hair to every other day at least, or 2/3 times a week. Your hair will thank you in the long run.
3. Over-conditioningBe cautious with conditioner. You may be applying a conditioner that's too heavy for your hair type, which can weigh it down. Or you may not be washing it out properly – another grease-giving culprit. And finally avoid placing your conditioner all over your hair, focus on the ends to avoid causing oily roots and lank lengths.

4. Over-brushingBrushing your hair too much can stimulate oil production, which at first looks glossy, but soon looks greasy. Again, stick to detangling the lengths and ends if you've got an obsessive hair brushing habit.



5. Your hairbrush is dirtyMORE FROM HAIR

How to know if short hair will suit you

14 brunette hair trends set to be HUGE this summer

"I wore Kylie Jenner-style wigs for a week"Your hairbrush can harbor all sorts of nasties – build-up of stale styling products and dust are only the obvious ones! A clogged brush will transfer these onto the hair, making it feel dirty, so make sure yours is cleaned properly on a regular basis.
6. Your hairbrush is full of hairA hairy brush might not seem like an offender, but if your hair is greasy (which it is otherwise you wouldn't be reading this) by using a brush clogged with hairs you'll only be transferring grease from old strands back onto your clean hair. Fail.

7. Applying the wrong productsYou may be choosing styling products that aren't compatible with your hair. Look for lightweight formulas and avoid ones that promise 'shine' and 'moisture' which would be better suited to dry or dull hair types.
8. Product build-up that needs detoxingStyling products can cause the scalp and strands to become clogged up. If you're a dry shampoo junkie (like most greasy hair sufferers), you might want to give your locks a detox by using a clarifying shampoo 2-4 times a month, or a product designed to exfoliate the scalp. It is the gateway to healthy hair, after all.


Source: http://www.cosmopolitan.com by Bridget March

Don't let your shampoo bottle fool you: Dry hair is not a hair type—it's a condition that can be treated. Your first step: Find out what's stripping strands of their natural oils. We asked experts in the field to nail down some culprits, as well as simple treatments to nix dry, damaged hair for good.
1. The Weather
“Summer includes overexposure to the sun, swimming, and products with alcohol, which can all dehydrate hair,” says Remington celebrity stylist Richard Marin. "And with winter comes extreme cold followed by overheated indoors, which can make hair parched and dry."

2. Smoothing Treatments
Too many smoothing treatments done close together can leave your locks super thirsty. “These treatments work effectively to smooth out hair and make it luscious and dreamy, but if they are done too frequently, the buildup of protein on the hair causes it to become brittle,” says hairstylist Sylvia Vaught, who's also the founder of L.A.-based home blowout service Blow Me.

3. Hormone Changes
“Birth control pills, pregnancy, and menopause are all times of physiological shifts within the body that can have an adverse effect on the hair, including dryness and brittleness,” says Vaught. She recommends seeing your doctor to discuss treatment options.
4. Using the Wrong Shampoo
Not all shampoos are created equal: Vaught warns against using your man’s drying shampoo when yours runs out. “You would be better off rinsing your hair a few times with just water to remove some of the oil, rather than risk the stripping effects of a shampoo that is not right for you,” she says.
5. Brushing Hair When Wet
“Remember that hair is most susceptible to breakage when it is wet,” says Vaught. This won’t necessarily dry the hair, but it will leave the ends brittle and lead to breakage down the entire strand. Instead of brushing wet hair, use a comb with a bit of leave-in conditioner on it.

​6. Daily Heat Styling
Whether it’s the dryer or flat iron, daily heat to the hair will strip the hair of moisture. “This causes quite a bit of unnecessary damage that can be avoided,” says Vaught. If heat is imperative, aim to keep the temperature below 400 degrees.

How to Fix Damage That's Already Been Done
1. Go Thicker in the Winter
“Dry and brittle hair is a common problem year round, but these dry winter months leave many searching for a magic moisturizing solution,” says Vaught. A simple fix: Go heavier on the conditioner. “Just as you may use a heavier face cream, your hair also needs a heavier dose of moisture. Try Kevin Murphy Hydrate Me ($27, kevinmurphy.com)—it packs a great moisture punch.”
2. Use an Ion Blow Dryer
“Ions dry the hair from the outside, versus a traditional dryer, which dries from within the hair shaft to the outer layer,” says Marin. “This makes a huge impact on the health of your hair and is a huge time saver, as ions dry hair faster.”
3. Straighten Hair When Wet
“One of my favorite quick-conditioning treatments is to use a wet/dry straight iron, the Remington Wet 2 Straight Iron ($22.99, target.com),” says Marin. “Apply argan oil onto damp hair, and run the iron over it for a quick heat conditioning treatment. You will notice a dramatic difference in just one application.”

4. ...Or Skip the Straightener All Together
If hair won’t stay completely straight, go for a different look. “How about using a salt texturized to create a bit of movement instead?” says Vaught. “R+Co has a great one called Rockaway Salt Spray ($25, randco.com).”
5. Deep Condition Once a Week
Mark one day on your calendar for a conditioning mask reminder. “Simply wash your hair, put on a deep conditioning mask, wrap your hair in a hot towel for 30 minutes, and voila,” says Vaught. Your hair will be silkier and smoother.
6. Use Sulfate-Free Formulas
These formulas are most commonly recommended for those with color-treated hair because sulfates fade color. However, they also remove moisture. “Make sure to wash and condition hair every time with sulfate-free formulas,” says Marin.

​Source: http://www.womenshealthmag.com