Why screening tests are important

Getting the right screening test at the right time is one of the most important things you can do for your health. Screening finds diseases like cancer or diabetes early, before you have symptoms, and when they’re easier to treat. Which test you should have depends on your age and your risk factors. Learn more about the screenings your doctor may recommend for you.

Breast cancer

Early detection of breast cancer greatly improves your odds of survival. That’s because the smaller the cancer is when it’s found, the better the chance for a surgical cure. Smaller breast cancers are also less likely to have spread to lymph nodes and other organs such as the lungs and brain. All women aged 50 and over are offered NHS breast screening every three years. Younger women with higher risk factors or specific concerns may also be referred to a hospital breast clinic.

Screening with mammography

Talk to your doctor about breast cancer screening. From the age of 50, women are offered NHS breast screening every three years. That’s being extended to women over 47 by 2012. These low-dose X-rays can detect a lump three years before you can feel it, but a normal mammogram does not completely rule out the possibility of breast cancer.

Cervical cancer

The cervix is the part of the uterus that extends into the vaginal cavity. Persistent infection with the human papillomavirus (HPV) is the major risk factor for cervical cancer (shown here, magnified). Routine screening can find abnormal precancerous cells on the surface of the cervix so they can be removed before they turn into cancer.

Smear test – cervical screening

Doctors use a smear test to screen for abnormalities which could lead to cancer of the cervix if they are not treated. In the surgery or clinic, the doctor or nurse collects a sample of cells from your cervix. These are then examined in a laboratory to find precancerous and cancer cells. The screening test is very effective in both preventing and finding cervical cancer early enough to cure it.

A vaccine for cervical cancer

The HPV vaccination programme began in September 2008 with the jab being offered to all 12 to 13 year old - and 17 to 18 year old - girls. The vaccine, called Cervarix, targets two strains of HPV - human papillomavirus. Not all cervical cancers are due to HPV and other strains of HPV can still cause cancer. So while these vaccines may greatly reduce the number of cervical cancer cases, it’s still important to have routine smear tests.

Osteoporosis and fractured bones

Osteoporosis is a condition in which bones become weak and fragile. It’s caused by bone loss, which accelerates in women after menopause. The first symptom is often a painful bone fracture that can occur with only a minor fall, blow or even just a twist of the body. It is possible to both prevent and treat osteoporosis, which the NHS says affects around three million people in the UK.

Osteoporosis screening tests

A test called dual energy X-ray absorptiometry (DXA) can measure bone mineral density and detect osteoporosis before fractures occur. It can also help predict the risk of future bone fractures. You may be offered a DXA scan if you are thought to be at a high-risk of developing osteoporosis.

Skin cancer

The most dangerous form of skin cancer is malignant melanoma (shown here). It’s a malignancy that affects the cells that produce pigment in the skin. Some people may have a genetic risk factor for melanoma, and the risk increases with overexposure to the sun and sunburn. Early treatment of skin cancer can be effective. And melanomas that are detected at a thinner stage can be treated more successfully than thick ones that have grown deeper into the skin. Basal cell and squamous cell skin cancers are common non-melanoma skin cancers.

Screening for skin cancer

Doctors say it is important to regularly check your own skin for anything unusual, like a mole that’s grown bigger or changed colour. If you see anything that concerns you, see your GP, who will decide whether you need to be referred for tests.

High blood pressure (hypertension)

Your risk for high blood pressure increases with age. It’s also related to your weight and certain lifestyle habits. High blood pressure can lead to severe complications without any prior symptoms, including an aneurysm. However, high blood pressure can be treated. When it is, you reduce your risk of complications such as heart disease, stroke and kidney failure. Finding out you have high blood pressure and then working with your doctor to manage it can pay huge health dividends.

Screening for high blood pressure

Blood pressure is expressed as two numbers. The first (systolic) is the pressure of your blood against your artery walls when the heart beats. The second (diastolic) is the pressure between beats. Normal adult blood pressure is less than 120/80. Blood pressure that is 140/90 or higher is considered high blood pressure. A reading between those two is considered prehypertension. How often blood pressure should be checked depends on how high it is and what other risk factors you have.

Cholesterol levels

A high level of LDL cholesterol is a major factor that increases the risk of developing heart disease and atherosclerosis - hardening and narrowing of the arteries - which is caused by plaque (seen here in orange) building up inside your arteries. It can progress without symptoms for many years. Over time it can lead to heart attack and stroke. Other atherosclerosis risk factors are high blood pressure, diabetes and smoking. Lifestyle changes and medications can lower your risk of cardiovascular disease.

Determining cholesterol levels

Doctors screen for problems with cholesterol by using a fasting blood lipid test. It’s a blood test that tells you your levels of total cholesterol, LDL “bad” cholesterol, HDL “good” cholesterol, and triglyceride (blood fat). Management decisions are based on the results. Anyone can ask for a cholesterol test, but this is especially important if you are over 40 or have risk factors such as heart disease, are overweight, have high blood pressure, diabetes or a family history of cardiovascular disease.

Type 2 diabetes

The NHS says diabetes affects two million people in England and Wales and it is thought that there are another 750,000 people who have the condition but are unaware of it. Diabetes can lead to complications such as heart disease and stroke, kidney disease, blindness from damage to the blood vessels of the retina (shown here) and nerve damage. However, especially when found early, diabetes can be controlled and complications avoided with diet, exercise, weight loss and medication when appropriate.

Screening for type 2 diabetes

A fasting blood glucose test is most often used to screen for diabetes and prediabetes. A vial of blood is taken after you’ve fasted at least eight hours and used to determine your blood sugar level. A level of between 6 and 7mmol/l indicates prediabetes. And 7mmol/l and above may indicate diabetes. Diabetes screening takes place in some pilot areas, but typically tests will be offered if your GP suspects you may be at risk of having diabetes.

Human Immunodeficiency Virus (HIV)

HIV is the virus that causes AIDS. It’s in the blood and other body secretions of infected individuals, even when there are no symptoms. It spreads from one person to another when blood or these secretions come into contact with the vagina, anal area, mouth, eyes or a break in the skin. There is still no cure or vaccine. However, theoretically, early treatment with anti-viral medications may help the body's immune system fight the virus.

HIV screening tests

HIV-infected individuals can remain symptom free for many years. The only way to know they are infected is with blood tests. The first test is called ELISA. It looks for antibodies to HIV in the blood. It’s possible not to be infected and still show positive on the test. So a second test called a Western blot assay is carried out for confirmation. If you are infected, you could still have a negative test result. Repeat testing is sometimes recommended. If you think you may have been exposed to HIV, ask your GP or sexual health clinic about the tests.

Preventing the spread of HIV

Most newly infected individuals test positive by two months after infection, but a small number can still test negative for up to six months. Abstinence or using latex barriers such as a condom or a dental dam is necessary to avoid potential infection of HIV and other sexually transmitted infections. If you have HIV and are pregnant, talk to your doctor or midwife about what needs to be done to reduce the risk of HIV infection in your unborn child.

Colorectal (or bowel) cancer

Colorectal - or bowel - cancer affects one in 20 women and one in 18 men according to NHS figures, the third most common type of cancer. The majority of colon cancers develop from colon polyps that are growths on the inner surface of the colon. After cancer develops it can invade or spread to other parts of the body. The way to prevent colon cancer is to remove colon polyps before they turn cancerous.

Screening for bowel cancer (colorectal cancer)

In 2006 the NHS began a bowel cancer screening programme using stool samples. It's offered to everyone aged between 60 and 69, every two years. For anyone at high risk, for example with a family history of bowel cancer, a colonoscopy can be performed. A doctor views the entire colon using a flexible tube and a camera. Polyps can be removed at the time of the test. A similar alternative is a flexible sigmoidoscopy that examines only the lower part of the colon. 

Glaucoma

Glaucoma is a condition that can result in blindness due to damage to the optic nerve. Primary open angle glaucoma is the most common type. This glaucoma often produces no symptoms until damage has begun. There is good evidence that treating elevated eye pressure in glaucoma can prevent blindness.

Glaucoma screening

It is important to have regular eye tests with an optician so that conditions like glaucoma can be picked up. Everyone over 40 should have an eye test every two years. People with a higher risk of glaucoma should be checked from the age of 30, these include people with a family history of glaucoma. Check ups with an optician are not usually free of charge, unless you are in a group entitled to free tests, such as people over 60 or those with conditions such as glaucoma or diabetes. All eye tests are free in Scotland.

Importance of health screening

Being proactive and discussing screening tests with your doctor makes good health sense. Some tests, such as a smear test, should be a routine part of every woman’s health care. Other tests become more or less important based on your risks. Proper screening won’t always prevent a disease, but it can find a disease early enough to give you the best chance of overcoming it.

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