Who's to blame for your thin, splitting nails? The dishes you wash each night, the dry atmosphere, your diet of chicken fingers and french fries?

First, let's get scientific. Onychoschizia is the official term for splitting fingernails, and if you've got 'em you're part of the 27 percent of women who do. Brittle nails fall into two basic categories: dry and brittle (too little moisture) and soft and brittle (often too much moisture).

So what's the underlying reason that's keeping you from the hand model career of your dreams? Most likely, it's nothing too bad. Splitting nails are very rarely related to a serious medical condition or vitamin deficiency. The majority of cases are due to the frequent wetting drying of the hands, so the condition is unsurprisingly common among house cleaners, nurses, and hairdressers. What can you do? And what if it is serious? Here's how to nail your nail care.

Keep your fingernails dry

If you find yourself elbow-deep in dirty dishes each night after dinner, do your nails a favor and wear cotton-lined rubber gloves. Wear these when you're exposed to harsh cleaning chemicals, too.

...And then moisturize

Water seeps moisture from your nails. That means each time you wash your hands you should rub a rich and fast-absorbing lotion in. Keep some L'Occitane 20% Shea Butter Hand Cream($12, Amazon) by the sink, and what the hell — couldn't hurt to keep another tube on your desk.

Be mindful of your manicures

Dry brittle nails are exacerbated by all those nail salon chemicals. Make the mani-pedi a special occasion, and don't leave nail polish on too long. The drying effect of polish continues even after the lacquer dries, so remove polish after five days, and avoid acetone-based nail polish removers.

...On the other hand

If you have soft, brittle nails (rather than dry brittle nails), a layer of polish may actually help. Know your nails, ladies.

Okay, but what if you do all that, and it turns out your body is trying to tell you something?

You need more iron

Low iron levels can cause brittle nails, according to the National Heart, Lung, and Blood Institute. (You might also feel fatigued, experience shortness of breath, or have bouts of headaches and dizziness.) A doctor can look at blood work and may recommend iron supplements. You can also fill your meals with iron-rich foods, like spinach, white beans, oysters, and dark chocolate.

You should have your thyroid checked

Brittle nails are one sign of low thyroid levels, along with fatigue, weight gain, dry skin, thinning hair, memory problems, depression, and constipation, according to Harvard Health Publishing.

Check to see if it's Raynaud's syndrome

Raynaud's syndrome is marked by poor blood flow to the fingers and toes which, in addition to brittle, thin, or weak nails, can also cause hands and feet to feel cold or numb, according to the National Institute of Arthritis and Musculoskeletal and Skin Diseases. Have a doc check it out to be on the safe side.

And then give yourself a high-five for your good nail health.