PITTSBURGH -- Losing your hair can be frightening and embarrassing.

But for millions of Americans, the cause of their hair loss may be as close as their medicine cabinet.

Linda Holden was stunned when she started losing her hair. It got so bad she had to start wearing a hair addition.

"I was very frightened when my hair started falling out," Holden said.

It turns out the root of Holden's problem was her arthritis medication.

She's not alone -- as many as 20 million American's may be losing their hair because of popular medications.

"There are numerous medications which can cause hair loss, including medications that are commonly used," Dr. Douglas Altchek, of the American Academy of Dermatology, said.

Medications used to treat everything from acne to arthritis to cholesterol and high blood pressure -- even some birth control pills -- can thin your hair. And it's not just prescription drugs.

Even ibuprofen and aspirin can cause hair loss if used regularly.

"A lot of the nasal decongestants used for colds are potentially some of the culprits. A lot of the medications that are used sometimes for acid reflux," Dr. Eric Alvarez, of the American Pharmacists Association, said.

Susan Kettering is with American Hair Loss Council and based in Pittsburgh.

"Doctors don't give you the detailed information. You take a pill, you're on it for three or four weeks and suddenly you wake up one day and realize that your hair is a little finer, a little thinner," Kettering said.

Altchek says it's up to the patients to voice concerns. If doctors determine the hair loss is linked to drugs, they may be able to help.

"In many cases, physicians can prescribe alternative medications," Altchek said.

That's not always possible if you are forced to stay on a drug -- but the benefits may far outweigh the risks.

"Obviously, if you are on a life-saving cholesterol drug, this is far more important than a minimal amount of hair loss you might suffer," Altchek said.

"It was a Catch-22. I was depressed about the hair loss but yet I was making progress in dealing with my illness," Holden said.

In the end, Holden's hair started to grow back once she was put on an alternative medication.

Now she wants others to be proactive, believing that using your head may just help you save your hair.

"They should investigate because there are so many avenues to pursue today as far as what they can do," Holden said.

But doctors say hair loss caused by medication is usually reversible once you stop taking the drug.

Adverse side effects should be listed on medications, so be sure to read all the information about a drug before taking it.