The routine screening tests critical to women's health

Doctors are much more capable of successfully treating many deadly diseases when they're detected early on, which is why routine preventive screening tests are critical. And certain tests are especially important for women. Mammograms, pap smears and colonoscopies have the potential to save millions of lives. But many women still don't know when they're supposed to start getting them or how often the tests are really needed.

A colonoscopy picked up Cynthia Trogisch's stage three colon cancer. The 61-year-old teacher had never been screened before.

"I don't know, we think we are invincible," she told CBS News. "I'm a fairly healthy person. I'm active, I have a lot of energy. And there were no symptoms."

Health experts recommend most women start screening for colorectal cancer at age 50, but Dr. Natasha Withers, a family physician at One Medical Group says screening for the deadly disease doesn't necessarily involve undergoing a colonoscopy. There are a number of other, less invasive options, including a test you can do at home, that may be appropriate for some patients. Which type of test your doctor recommends and how often you need to be screened may vary depending on your medical history and other factors.

Guidelines for other screening tests are equally confusing. There's been an ongoing debate about when to start mammograms. Many groups, including the American Cancer Society, say women at average risk for breast cancer should get one every year starting at age 40.

Experts say that while women should certainly be vigilant about undergoing tests for these common cancers, another good way to stay healthy is to have regular check-ups to monitor blood pressure, cholesterol levels and diabetes risk, since heart disease is still the top killer of women in the U.S.

"I think the importance of knowing is just being familiar with your health," Withers said, "being in charge of your health and being a partner with your doctor and making sure you're making healthy choices."

Your physician's decision to order certain screening tests at an earlier or later age than average may have to do with a number of personalized factors such as age, weight, existing health conditions and whether you have a family history of disease.

For example, women who test positive for mutations in the BRCA 1 and BRCA 2 genes, which significantly raise the risk for breast cancer, are encouraged to begin screenings earlier.

Withers added that when it comes to cervical cancer screenings, women should be sure and get HPV and Pap smear tests. Physicians recommend that women start getting the Pap test at age 21 every three years.

"Over the age of 30 we are actually recommending a pap smear every five years as long as you've had a pap smear in addition to human papilloma testing," said Withers.

Trogisch says her experience with colon cancer has changed the way she views routine screening tests, and she encourages friends and family members to seek them out. "The more we speak to each other openly the more we are going to save lives," she said.

Patients should become familiar with the screening guidelines from organizations such as the U.S. Preventive Services Task Force, American College of Obstetrics and Gynecology, and the American Heart Association, then discuss a screening plan with their doctor.

Mammography: The USPSTF recommends screening every two years starting at age 50, but ACOG suggests women get a mammogram each year beginning at age 40.

Colonoscopy: The USPSTF says most patients should begin colorectal cancer screening with a colonoscopy at age 50 and undergo the test every 10 years, usually until the age of 75. A doctor may determine that sigmoidoscopy and fecal blood testing is sufficient. The American Cancer Society outlines similar recommendations.

Pap and HPV tests: The USPSTF recommends screening for cervical cancer in women age 21 to 65 years old with Pap smear once every three years. For women who wish to be screened less frequently, the panel recommends women age 30 to 65 have both a Pap smear and HPV test every five years. ACOG has similar recommendations.

Blood pressure test: The AHA recommends patients have their blood pressure taken at least once each year starting at age 20.

Lipid panel: The AHA recommend testing cholesterol and triglycerides levels every 4 to 6 years.

Blood glucose tests: Screening for diabetes should occur at least every three years starting at age 45, according to AHA.

Finally, what about men? See our report on the medical screening tests crucial for men's health.