Genetic testing is a type of medical test that looks for changes, sometimes called variants or mutations, in your DNA. DNA contains the genetic instructions in all living things. Often, these changes have no effect, but sometimes, even a small change in DNA can cause disease or other health conditions.

Genetic tests take a sample of your blood or tissues and check your cells to look for any changes in:

• Genes are parts of DNA found in your cells that carry information that controls what you look like and how your body works. Many genes tell your body how to make proteins, which are needed for your body to work correctly.
  • Genome sequencing is a process that checks all your DNA.
  • Exome sequencing is a process that only checks the parts of your DNA that provide instructions to make proteins.
• Proteins do most of the work in your cells. If there are changes in the amount and activity level of proteins, they might be due to changes in the genes that produce those proteins.
• Chromosomes are thread-like structures in your cells. Each chromosome is made up of DNA tightly packaged around proteins. People usually have 23 pairs of chromosomes that contain all their DNA.

Most of the time, genetic testing is done through your health care provider. This is called clinical testing. It is done to find out about an inherited disorder (passed down through families) and to help make decisions about your care.

Other ways to get genetic testing include:

• Research-based testing is a genetic test done as part of a research study (clinical trial).
• Direct-to-consumer (DTC) testing is a genetic test that allows you to send a DNA sample and get the results. You may do this to learn about your ancestry or your risk for certain diseases.

Genetic testing may be done for many different reasons, including to:

• Find genetic diseases in a fetus. This is a type of prenatal testing.
• Screen newborn babies for certain treatable conditions.
• Lower the risk of genetic diseases in embryos that were created using assisted reproductive technology.
• Find out if you carry a gene for a certain disease that could be passed on to your children. This is called carrier testing.
• See whether you are at an increased risk of getting a specific disease. This may be done for a disease that runs in your family.
• Diagnose certain diseases.
• Identify genetic changes that may be causing or contributing to a disease that you were already diagnosed with.
• Help guide your provider in deciding the best medicine and dosage for you. This is called pharmacogenomic testing.
• To check for, monitor, or manage a disease. This is sometimes used to help find the best cancer treatment.
• To confirm the biological father (paternity) of a child, or how much genetic information is shared with other relatives.
• To explore the likelihood of having or developing certain physical traits, such as hair color or facial dimples, or to learn about your ancestry.
• To help advance our understanding of genetic conditions, learn how genes work, and find unknown genes.

Genetic tests are often done on a blood or cheek swab sample. But they may also be done on samples of hair, saliva, skin, amniotic fluid (the fluid that surrounds a fetus during pregnancy), or other tissue. The sample is sent to a laboratory. There, a lab technician will use one of several different techniques to look for genetic changes.

The benefits of genetic testing include:

• Helping your provider make recommendations for the management or monitoring of a genetic condition.
• Giving you more information for making decisions about your health and your family's health:
  • If you find out that you are at risk for a certain disease, you might take steps to lower that risk. For example, you may find out that you should be screened for a disease earlier and more often. Or you might decide to make healthy lifestyle changes.
  • If you find out that you are not at risk for a certain disease, then you can talk to your provider about when it would be appropriate to schedule checkups or screenings.
  • A test could give you information that helps you make decisions about having children.
• Identifying genetic disorders early in life so that treatment can start as soon as possible.

The physical risks of the different types of genetic testing are small. But there can be emotional, social, or financial drawbacks:

• Depending on the results, you may feel angry, depressed, anxious, or guilty. This can be especially true if you are diagnosed with a disease that does not have effective treatments.
• Despite the protections that are in place, you may be worried about genetic discrimination in employment or insurance.
• Genetic testing may give you limited information about a genetic disease. For example, it cannot tell you whether you will have symptoms, how severe a disease might be, or whether a disease will get worse over time.
• Genetic testing results might be inconclusive. For example, you might keep getting negative results or not get an answer at all.
• Some genetic tests may give you results that you didn't expect. For example, if you are tested to check for the cause of a rare disease, and a different variant is found that puts you at increased risk for something else that was previously unknown.
• Some genetic tests are expensive, and health insurance might only cover part of the cost. Or they may not cover it at all.

The decision about whether to have genetic testing is complex. In addition to discussing the test with your provider, you can meet with a genetic counselor. Genetic counselors have specialized degrees and experience in genetics and counseling. They can help you understand the tests and weigh the risks and benefits. If you do take a test, they can explain the results and make sure that you have the support that you need.

Moles are growths on the skin. They happen when pigment cells in the skin, called melanocytes, grow in clusters. Moles are very common. Most people have between 10 and 40 moles. A person may develop new moles from time to time, usually until about age 40. In older people, they tend to fade away.

Moles are usually pink, tan or brown. They can be flat or raised. They are usually round or oval and no larger than a pencil eraser.

About one out of every ten people has at least one unusual (or atypical) mole that looks different from an ordinary mole. They are called dysplastic nevi. They may be more likely than ordinary moles to develop into melanoma, a type of skin cancer. You should have a health care professional check your moles if they look unusual, grow larger, change in color or outline, or in any other way.

NIH: National Cancer Institute

Your pituitary gland is a pea-sized gland at the base of your brain. The pituitary is the "master control gland" - it makes hormones that affect growth and the functions of other glands in the body.

Pituitary tumors are common, but often they don't cause health problems. Most people with pituitary tumors never even know they have them. The most common type of pituitary tumor produces hormones and disrupts the balance of hormones in your body. This can cause endocrine diseases such as Cushing's syndrome and hyperthyroidism.

Symptoms of pituitary tumors include:

• Headaches
• Vision problems
• Nausea and vomiting
• Problems caused by the production of too many hormones

Pituitary tumors are usually curable. Treatment is often surgery to remove the tumor. Other options include medicines, radiation therapy, and chemotherapy.

Some people think that tanning gives them a healthy glow. But tanning, either outdoors or indoors with a tanning bed, is not healthy at all. It exposes you to harmful rays and puts you at risk for health problems such as melanoma and other skin cancers.

Sunlight travels to earth as a mixture of both visible and invisible rays. Some of the rays are harmless to people. But one kind, ultraviolet (UV) rays, can cause problems. They are a form of radiation. UV rays do help your body make vitamin D, but too much exposure damages your skin. Most people can get the vitamin D that they need with only about 5 to 15 minutes of sun exposure two to three times a week.

There are three types of UV rays. Two of them, UVA and UVB, can reach the earth's surface and affect your skin. Using a tanning bed also exposes you to UVA and UVB.

UVB rays can cause sunburn. UVA rays can travel more deeply into the skin than UVB rays. When your skin is exposed to UVA, it tries to protect itself from further damage. It does this by making more melanin, which is the skin pigment that makes your skin darker. That's what gives you a tan. This means that your tan is a sign of skin damage.

Since tanning means overexposure to UV rays, it can damage your skin and cause health problems such as:

• Premature skin aging, which can cause your skin to become thickened, leathery, and wrinkled. You may also have dark spots on your skin. These happen because long-term exposure to UV rays makes your skin less elastic. The more sun exposure you have, the earlier your skin ages.
• Skin cancers, including melanoma. This can happen because the UV light damages the DNA of your skin cells and interferes with your body's ability to fight the cancer.
• Actinic keratosis, a thick, scaly patch of skin that usually forms on areas exposed to the sun, such as the face, scalp, back of the hands, or chest. It can eventually become cancerous.
• Eye damage, including cataracts and photokeratitis (snow blindness)
• A weakened immune system, which can increase your sensitivity to sunlight, decrease the effects of vaccines, and cause you to have reactions to certain medicines.

• Limit sun exposure. Try to stay out of the sun between 10 a.m. and 4 p.m., when its rays are strongest. But remember that you still get sun exposure when you are outside on cloudy days or are in the shade.
• Use sunscreen with sun protective factor (SPF) 15 or higher. It should also be a broad-spectrum sunscreen, which means that it gives you both UVA and UVB protection. If you have very light skin, use SPF 30 or higher. Apply sunscreen 20-30 minutes before going outside and reapply it at least every 2 hours.
• Wear sunglasses that block both UVA and UVB rays. Wrap-around sunglasses work best because they block UV rays from sneaking in from the side.
• Wear a hat. You can get the best protection with a wide-brimmed hat that is made out of a tightly woven fabric, such as canvas.
• Wear protective clothing such as long-sleeved shirts and long pants and skirts. Clothes made from tightly woven fabric offer the best protection.

It is also important to check your skin once a month. If you do see any new or changing spots or moles, go see your health care provider.

Indoor tanning is not better than tanning in the sun; it also exposes you to UV rays and damages your skin. Tanning beds use UVA light, so they expose you to a higher concentration of UVA rays than you would get by tanning in the sun. Tanning lights also expose you to some UVB rays.

Some people think that getting a "base tan" in a tanning salon can protect you when you go in the sun. But a "base tan" causes damage to your skin and will not prevent you from getting sunburn when you go outside.

Indoor tanning is particularly dangerous for younger people. You have a higher risk of melanoma if you started doing indoor tanning while you were a teen or young adult.

Some research shows that frequent tanning may even be addictive. This can be dangerous because the more often you tan, the more damage you do to your skin.

There are other ways to look tan, but they are not all safe:

• Tanning pills have a color additive that turns your skin orange after you take them. But they can be dangerous and are not approved by the Food and Drug Administration (FDA).
• Sunless tanners have no known risk for skin cancer, but you do have to be careful. Most spray tans, lotions, and gels use DHA, a color additive that makes your skin look tan. DHA is considered safe for use on the outside of your body by the FDA. You need to make sure it doesn't get into your nose, eyes, or mouth. If you use a spray tan, be careful not to breathe in the spray. Also, remember that these "tans" do not protect you from UV rays when you go outside.

Your adrenal glands are two small organs that sit on top of each kidney. The adrenal glands make different types of hormones you need to stay alive and healthy. Hormones are chemicals that travel in your bloodstream and control how different parts of your body work.

The adrenal glands make the hormones cortisol, aldosterone, adrenaline, and noradrenaline. They also make hormones that your body uses to make sex hormones (estrogen and testosterone). All of these hormones do many important jobs, including:

• Turning food into energy and managing blood sugar levels
• Balancing salt and water
• Keeping blood pressure normal
• Responding to illness and stress (your "fight or flight" response)
• Timing when and how fast a child develops sexually
• Supporting pregnancy

When you have an adrenal gland disorder, your body makes too much or too little of one or more hormones. The symptoms depend on the type of problem you have and how much it affects the hormone levels in your body.

There are many types of adrenal gland disorders, including:

• Addison's Disease - a condition in which the adrenal glands don't make enough cortisol
• Cushing's Syndrome - a condition caused by too much cortisol in the body, often from taking steroid medicines for a long time
• Aldosterone-producing adenoma - a benign tumor (not cancer) that makes too much aldosterone and may cause serious high blood pressure
• Hereditary paraganglioma-pheochromocytoma - an inherited condition causing different types of tumors that make adrenaline and other hormones. Some tumors may become cancerous.
• Adrenal gland cancer - cancerous tumors, including adrenocortical carcinoma and neuroblastoma
• Congenital Adrenal Hyperplasia (CAH) - a group of inherited disorders in which the adrenal glands don't make enough cortisol. The most common type is 21-hydroxylase deficiency (also called CAH1). In the United States, newborn babies get a blood test to see if they have CAH. People born with CAH may not have symptoms until childhood or later in life.

The cause of adrenal gland disorders depends on the type of disorder you have. Causes can include:

• Medicines such as steroids
• A problem in another gland, such as the pituitary gland. The pituitary gland releases hormones that affect how the adrenal glands work.
• Changes in genes (mutations). These changes can cause the adrenal glands to make too much or too little of one or more hormones.
• Infections

In many cases the cause of the problem isn't clear.

Health care providers use different tests to check for adrenal disorders depending on your symptoms and health history. For example, you may have tests of your blood, urine (pee), or saliva (spit). These tests check your hormone levels. Your provider may order x-rays, CT scans, or MRI scans to look for tumors.

Different types of adrenal gland disorders have different treatments. They include medicines and surgery. Radiation therapy is sometimes a treatment for tumors. There are treatments to cure certain adrenal gland disorders. For other disorders, treatments can manage your symptoms.

NIH: National Institute of Child Health and Human Development