You might not be as obsessed as Romesh Sharma of India, documented in the Guinness Book of World Records for having grown a talon of 24 1/2 inches in 12 years, or as cautions of your nails gold covers to protect their foot-long nails.

But if you sit on your hands because you're embarrassed to show them in public -- your nails are split and broken, you bite them, or nibble on your cuticles -- you're not alone. There are people who get depressed when a nail breaks off, who won't go out in public with ragged nails or chipped polich and plan their social schedules around drying their nails.

Whatever, nails are noticed. Who isn't aghast someone's dirty ones?

"Hands do not lie," says Anna Chennault, who is known around town as the widow of World War ii Flying Tigers chief Lt. Gen. Clare Lee Chennault, as a Republican hostess and fund-raiser and also for her perfect, elegant nails. She gives herself a manicure every other day.)

You can change your face and your neck and you can dye your hair but hands tell the truth about a person's age," she says. "And there's nothing worse than someone with dirty fingernails -- it shows that a person is not very tidy or organized."

Roscoe Dellums, wife of Rep. Ronald Dellums (D-CALIF.), used to have palm trees, footballs and caricatures of her husband painted on her finger- and toenails by two nail artists at their salon called Nettie and Isabel's.

"I loved it, " says Mrs. Dellums. "It was fun and my friends would all wait to see what I would come in with next on my nails.

The salon has since closed, she has started at Georgetown Law School, and her nails "are horrible, " she says, "shattered by my schoolbooks and nerves. My ego is somewhere else now and I have no time for nails."

Whether you pay attention to your nails or not, it's a big business: Sales of nail polishes and enamels totaled $200 million in 1977 according to Drug Topics magazine. Washington's Elizabeth Arden salon does about 650 manicures a week at $7.50 each. And not only do women experiment with all the new nail strengtheners, buffers and creams, but so do men.

"I've seen more men over the last 10 years, with the new interest in men's grooming, take better care of their nails and even use a coat or two of clear nail polish," says nail expert Dr. Edward Krull, chairman of the dermatology department of Henry Ford Hospital in Detroit.

"And I'm not talking about theatrical people -- it's mostly the business executive."

Women have always been almost fanatic on the subject of nails, and nail fads come and go -- remember the tigress filed-to-a-point red nails of the '50s, the kooky nail designs, Cher's inch-long squared-off talons? -- and so do the products. Now creams for horses' hooves have been adapted for human nails and there are nail strengtheners containing nylon threads.

Gelatin, whether in powdered or capsule form, long has been billed as a nail-builder, but most dermatologists don't put much faith in it, although some studies say it helps.

"Gelatin is a poor protein," says Dr. Nardo Zaias, a Miami dermatologist and leading nail expert and author of the chapter on nails in several dermatological textbooks. "It has common amino acids that you can get anywhere."

"In general, gelatin has been of little benefit to our problems with nails," says Dr. Krull."I have not really been impressed that gelatin has in any way affected the hardness of nails and nail growth."

Nail-biting, which doctors say in generally more common in men than women (and not uncommon among monkeys), is a habit that people form under stress. Doctors say it is difficult to treat.

"People have tried various things like painting them with unpleasantly flavored substances -- quinine products and the like -- but sometimes focusing on the nail makes people bite them more, " says Dr. Krull.

"I truthfully don't have a good suggestion about what works -- except maybe hypnosis in some cases," says Dr. Zaias. "In children, however, if a hyperactive child is biting his nails, the best thing is don't make an issue of it. A great way for a child to aggravate his parents is to bite his nails just to get attention. Nothing is going to happen if they bite their nails and chances are they will grow out of it."

Everyone has their oven formula for beautiful nails. Washington actress Nancy Lepp, whose hands have been used in advertisements, is constantly besieged with questions about how she gets her nails to grow so long.

"I did not always have good nails," she says. "I simply decided it was mind over matter. There are some secrets that I have. Gelatin does not work but 1i think that zinc tablets have helped me; I never use an emery board, but only a diamond file on my nails; i never use cuticle scissors but push my cuticles back with a towel when my hands are soft; I polish my nails every chance I get and have had as many as 20 coats of polish on at one time."

Anna Chennault, who leads her own international aviation and transportation consulting firm, says that fingernail polish of different colors gives her a different mood every day. "Sometimes I feel like a darker shade and sometimes a lighter tone and sometimes just natural color. It sort of changes with the mood or feelings. But I don't spend a lot of time doing them -- I usually do it while reading."

Connie Caravalho, who has been a manicurist for 20 years, the last six with Elizabeth Arden, says her problem customers are "housewifes who keep their hands in water too long. They should have a manicure once a week if they can afford it and rub cream into their nails every chance they get."

For customers who type a lot, she files the nail into a square shape and tells them to put on as many as five to six coats of polish a day to strengthen the nail.

Typists, of course, should try for killer nails. Bosses may not appreciate the fact that very long nails can cut typing speeds as much as 20 percent.

"It's almost impossible to work a typewriter with long nails, unless they are super strong." says Royal Sanders, an office manager for a real-estate firm. "I've tried everything including some new cream that you rub into your nails that smells like apricots, but nothing works. And the combination between typing, housework and my daughter doesn't give me enough time to keep them manicured. You can't have Cher fingernails unless you have Cher's maid."