Fasting blood sugar levels give vital clues about how a person's body is managing blood sugar.Blood sugar tends to peak about an hour after eating and declines after that.
High fasting blood sugar levels point to insulin resistance or diabetes, while abnormally low fasting blood sugar could be due to diabetes medications.
Knowing when to test and what to look for can help keep people stay healthy, especially if they have diabetes or are at risk of developing the condition.
Cholesterol is a waxy, fat-like substance that's found in your blood and every cell of your body. You need some cholesterol to keep your cells and organs healthy.
Your liver makes all the cholesterol your body needs. But you can also get cholesterol from the foods you eat, especially meat, eggs, poultry, and dairy products.
Foods that are high in dietary fat can also make your liver produce more cholesterol.
There are two main types of cholesterol:
low-density lipoprotein (LDL), or "bad" cholesterol, and high-density lipoprotein (HDL), or "good" cholesterol.
A cholesterol test is a blood test that measures the amount of each type of cholesterol and certain fats in your blood.
A high-density lipoprotein (HDL) test measures the level of good cholesterol in your blood. Cholesterol is a waxy substance that’s found in all of the cells in your body. It has several different functions, including helping to build your body’s cells. Cholesterol is carried through the bloodstream attached to proteins called lipoproteins.
Two types of cholesterol in your body are HDL, which is the good cholesterol, and low-density lipoprotein (LDL), or bad cholesterol. HDL is known as the good cholesterol because it carries LDL, triglycerides, and harmful fats and returns them to your liver for processing. When HDL reaches your liver, the liver breaks down the LDL, turns it into bile, and removes it from your body.
The body is made up mostly of LDL cholesterol. LDL is considered bad cholesterol because high levels in the body can lead to plaque buildup in the arteries. This can result in heart disease or a stroke. Research has shown people with healthy HDL cholesterol levels are at a lower risk for coronary artery disease. Your doctor can check your cholesterol levels using a simple test.
LDL stands for low-density lipoprotein, a type of cholesterol found in your body. LDL is often referred to as bad cholesterol. This is because too much LDL results in a build-up of cholesterol in your arteries, which can lead to heart attacks and strokes.
If you have high levels of good cholesterol, called high-density lipoprotein (HDL), it may decrease your risk of developing heart disease. HDL helps transport LDL cholesterol to your liver to be broken down and thus helps avoid damage to your heart.
It measures the following things:
White blood cells (WBCs). These help to fight infections. If you have high WBC levels, it tells your doctor you have inflammation or infection somewhere in your body. If it’s low, you could be at risk for infection.
RBC (red blood cell count). This is the number of red blood cells you have. These are important because they deliver oxygen through your body. They also help carry carbon dioxide. They also help carry carIf your RBC count is too low, you may have anemia or another condition.
Hb or Hgb (hemogolobin). This is the protein in your blood that holds the oxygen.
Hct (hematocrit). This value provides information about how much of your blood is comprised of red blood cells. A low score on the range scale may be a sign that you have too little iron, the mineral that helps produce red blood cells. A high score could mean you’re dehydrated or have another condition.
MCV (mean corpuscular volume). This is the average size of your red blood cells. If they’re bigger than normal, your MCV goes up. That could happen if you have low vitamin B12 or folate levels. If your red blood cells are smaller, you could have a type of anemia.
Platelets. These play a role in clotting. This test measures the number of platelets in your blood.
Urea nitrogen is a normal waste product that your body creates after you eat. Your liver breaks down the proteins in your food and while it does that, it creates blood urea nitrogen, also known as BUN. Your liver releases the substance into the blood, and it eventually ends up in your kidneys.
When your kidneys are healthy, they remove the BUN, usually leaving a small amount of it in the blood. But for the most part, your kidneys get rid of it by flushing it out of your body through urine.
When your kidneys are not healthy, they have trouble removing BUN and leave more of it in your blood.
The blood urea nitrogen test, which is also called a BUN or serum BUN test, measures how much of the waste product you have in your blood. If your levels are off the normal range, this could mean that either your kidneys or your liver may not be working properly.
This test measures the amount of uric acid in your blood or urine. Uric acid is a normal waste product that's made when the body breaks down chemicals called purines.
Purines are substances found in your own cells and also in some foods. Foods with high levels of purines include liver, anchovies, sardines, dried beans, and beer.
Most uric acid dissolves in your blood, then goes to the kidneys. From there, it leaves the body through your urine. If your body makes too much uric acid or doesn't release enough into your urine, it can make crystals that form in your joints. This condition is known as gout.
Gout is a form of arthritis that causes painful inflammation in and around the joints. High uric acid levels can also cause other disorders, including kidney stones and kidney failure.
A triglycerides test measures the amount of triglycerides in your blood. Triglycerides are a type of fat in your body. If you eat more calories than you need, the extra calories are changed into triglycerides.
These triglycerides are stored in your fat cells for later use. When your body needs energy, triglycerides are released into your bloodstream to provide fuel for your muscles to work.
If you eat more calories than you burn off, especially calories from carbohydrates and fats, you may get high triglyceride levels in your blood.
High triglycerides may put you at greater risk for a heart attack or stroke.
An alkaline phosphatase (ALP) test measures the amount of ALP in your blood. ALP is an enzyme found throughout the body, but it is mostly found in the liver, bones, kidneys, and digestive system.
When the liver is damaged, ALP may leak into the bloodstream. High levels of ALP can indicate liver disease or bone disorders.
Other names: ALP, ALK, PHOS, Alkp, ALK PHOS
AST (aspartate aminotransferase) is an enzyme that is found mostly in the liver, but also in muscles. When your liver is damaged, it releases AST into your bloodstream.
An AST blood test measures the amount of AST in your blood. The test can help your health care provider diagnose liver damage or disease.
Other names: SGOT test, serum glutamic oxaloacetic transaminase test; aspartate transaminase test
ALT, which stands for alanine transaminase, is an enzyme found mostly in the liver. When liver cells are damaged, they release ALT into the bloodstream.
An ALT test measures the amount of ALT in the blood. High levels of ALT in the blood can indicate a liver problem, even before you have signs of liver disease, such as jaundice, a condition that causes your skin and eyes to turn yellow. An ALT blood test may be helpful in early detection of liver disease.
Other names: Alanine Transaminase (ALT), SGPT, Serum Glutamic-Pyruvic Transaminase, GPT
Iron is a mineral in your body that comes from foods like red meat and fortified cereals or from supplements you take. You need iron to make red blood cells.
Iron is also an important part of hemoglobin, a protein in your blood that helps carry oxygen from your lungs to the rest of your body.
An iron test can show if you have too much or too little of this mineral in your system. It can check for conditions like anemia , or iron overload (excess iron).
A calcium blood test can find out whether you have too much or too little of this key mineral in your bloodstream. It’s often part of a routine screening.
This test helps screen for and diagnose diseases that affect your bones, heart, nerves, kidneys, and other organs.
Cacium is the most plentiful mineral in your body. Your body uses it to:
Strengthen your bones and teeth
Contract your muscles
Narrow and widen blood vessels
Send and receive nerve messages
Clot your blood
Almost all of your body's calcium is stored in your bones. A very small amount -- about 1% -- is in your blood. Calcium in your blood comes in two forms:
Free calcium is not attached to anything else in your blood.
Bound calcium is attached to a protein called albumin or other substances in your blood.
Phosphate is what you get when you combine the mineral phosphorus with oxygen. When you eat certain foods such as beans, nuts, cereal, milk, eggs, beef, chicken, and fish phosphorous enters your intestines. When it meets up with oxygen, it becomes phosphate.
Most phosphates team up with calcium to build and repair your bones and teeth. Some support your muscles and nerves.
Though you absorb phosphate in the intestines, it's filtered and removed through your kidneys.
Abnormal phosphate levels with symptoms such as bone problems, fatigue and weakness may point to a kidney disorder.
A sodium blood test measures the amount of sodium in your blood. Sodium is a type of electrolyte. Electrolytes are electrically charged minerals that help maintain fluid levels and the balance of chemicals in your body called acids and bases. Sodium also helps your nerves and muscles work properly.
You get most of the sodium you need in your diet. Once your body takes in enough sodium, the kidneys get rid of the rest in your urine. If your sodium blood levels are too high or too low, it may mean that you have a problem with your kidneys, dehydration, or another medical condition.
A potassium blood test measures the amount of potassium in your blood. Potassium is a type of electrolyte. Electrolytes are electrically charged minerals in your body that help control muscle and nerve activity, maintain fluid levels, and perform other important functions.
Your body needs potassium to help your heart and muscles work properly.
Potassium levels that are too high or too low may indicate a medical problem.
A creatinine blood test measures the level of creatinine in the blood. Creatinine is a waste product that forms when creatine, which is found in your muscle, breaks down. Creatinine levels in the blood can provide your doctor with information about how well your kidneys are working.
Each kidney has millions of small blood-filtering units called nephrons. The nephrons constantly filter blood through a very tiny cluster of blood vessels known as glomeruli. These structures filter waste products, excess water, and other impurities out of the blood. The toxins are stored in the bladder and then removed during urination.
Creatinine is one of the substances that your kidneys normally eliminate from the body. Doctors measure the level of creatinine in the blood to check kidney function.
High levels of creatinine may indicate that your kidney is damaged and not working properly.
A c-reactive protein test measures the level of c-reactive protein (CRP) in your blood. CRP is a protein made by your liver. It's sent into your bloodstream in response to inflammation.
Inflammation is your body's way of protecting your tissues if you've been injured or have an infection. It can cause pain, redness, and swelling in the injured or affected area. Some autoimmune disorders and chronic diseases can also cause inflammation.
Normally, you have low levels of c-reactive protein in your blood. High levels may be sign of a serious infection or other disorder.
TSH stands for thyroid stimulating hormone. A TSH test is a blood test that measures this hormone. The thyroid is a small, butterfly-shaped gland located near your throat. Your thyroid makes hormones that regulate the way your body uses energy. It also plays an important role in regulating your weight, body temperature, muscle strength, and even your mood.
TSH is made in a gland in the brain called the pituitary. When thyroid levels in your body are low, the pituitary gland makes more TSH. When thyroid levels are high, the pituitary gland makes less TSH.
TSH levels that are too high or too low can indicate your thyroid isn't working correctly.
A thyroxine test helps diagnose disorders of the thyroid. The thyroid is a small, butterfly-shaped gland located near the throat. Your thyroid makes hormones that regulate the way your body uses energy.
It also plays an important role in regulating your weight, body temperature, muscle strength, and even your mood. Thyroxine, also known as T4, is a type of thyroid hormone.
This test measures the level of T4 in your blood. Too much or too little T4 can indicate thyroid disease.
The thyroid gland is located in the neck, just below the Adam’s apple. The thyroid creates hormones and controls how your body uses energy and your body’s sensitivity to other hormones.
The thyroid produces a hormone called triiodothyronine, known as T3. It also produces a hormone called thyroxine, known as T4. Together, these hormones regulate your body’s temperature, metabolism, and heart rate.
Most of the T3 in your body binds to protein. The T3 that doesn’t bind to protein is called free T3 and circulates unbound in your blood. The most common kind of T3 test, known as the T3 total test, measures both kinds of T3 in your blood.
By measuring the T3 in your blood, your doctor may be able to determine if you have a thyroid problem.
Vitamin D is a nutrient that is essential for healthy bones and teeth. There are two forms of vitamin D that are important for nutrition: vitamin D2 and vitamin D3.
Vitamin D2 mainly comes from fortified foods like breakfast cereals, milk, and other dairy items. Vitamin D3 is made by your own body when you are exposed to sunlight. It is also found in some foods, including eggs and fatty fish, such as salmon, tuna, and mackerel.
In your bloodstream, vitamin D2 and vitamin D3 are changed into a form of vitamin D called 25 hydroxyvitamin D, also known as 25(OH)D.
A vitamin D blood test measures the level of 25(OH)D in your blood. Abnormal levels of vitamin D can indicate bone disorders, nutrition problems, organ damage, or other medical conditions.
The free prostate-specific antigen test, known as the free PSA test, is used to help detect signs of prostate cancer. The test measures the level of unbound prostate-specific antigen in the blood, which can help doctors to diagnose issues like inflammation of the prostate or cancer.
Free PSA tests are often used alongside other PAS tests to confirm a diagnosis or test results. Free PSA tests can also be used instead of a biopsy if the doctor suspects prostate cancer, but a biopsy may still be needed.
A prostate-specific antigen (PSA) test measures the level of PSA in your blood. The prostate is a small gland that is part of a man's reproductive system. It is located below the bladder and makes a fluid that is part of semen.
PSA is a substance made by the prostate. Men normally have low PSA levels in their blood. A high PSA level may be a sign of prostate cancer, the most common non-skin cancer affecting American men. But high PSA levels can also mean noncancerous prostate conditions, such as infection or benign prostatic hyperplasia, a noncancerous enlargement of the prostate.
A vitamin B-12 level test checks the amount of vitamin B-12 in the blood or urine to gauge the body's overall vitamin B-12 stores.
Vitamin B-12 is necessary for several bodily processes, including nerve function and the production of DNA and red blood cells.
A person whose vitamin B-12 levels are outside of the normal range will require treatment.
Low levels of the vitamin can cause neurological symptoms, as well as fatigue, constipation, and weight loss. High B-12 levels may indicate liver disease, diabetes, or another condition.
Ferritin is a protein in blood cells that stores iron.
Doctors use ferritin blood tests to check the levels of iron in a person's blood and help diagnose many health conditions. These conditions include:
iron-deficiency anemia, or a low red blood cell count
hemochromatosis, a condition wherein there is too much iron in the body
A total iron binding capacity (TIBC) test is a type of blood test that gauges whether there’s too much or too little iron in your bloodstream.
Iron is a type of mineral found in all of the body’s cells. You get the iron you need through your diet. Once iron enters the body, it’s carried throughout your bloodstream by a protein called transferrin, which is produced by your liver. The TIBC test evaluates how well transferrin carries iron through your blood.
In your blood, iron helps form hemoglobin. Hemoglobin is an important protein in red blood cells that helps carry oxygen throughout the body so it can function normally. Iron is considered an essential mineral because hemoglobin can’t be made without it.
Cancer antigen 15-3 (CA15-3) is a protein made by a variety of cells, particularly breast cancer cells. The protein moves into the blood, where it can be measured.
CA15-3 levels are higher than normal in most women with breast cancer that has spread to other parts of the body (called metastatic breast cancer).
Not all types of breast cancer will cause CA 15-3 levels to rise, as some types of cancer cells don’t over-produce the antigen.
A CA 125 test may be used to monitor certain cancers during and after treatment. In some cases, a CA 125 test may be used to look for early signs of ovarian cancer in people with a very high risk of the disease.
A CA 125 test isn't accurate enough to use for ovarian cancer screening in general because many noncancerous conditions can increase the CA 125 level.
Many different conditions can cause an increase in CA 125, including normal conditions, such as menstruation, and noncancerous conditions, such as uterine fibroids. Certain cancers may also cause an increased level of CA 125, including ovarian, endometrial, peritoneal and fallopian tube cancers.
This test measures the amount of a protein called CA 19-9 (cancer antigen 19-9) in the blood. CA 19-9 is a type of tumor marker. Tumor markers are substances made by cancer cells or by normal cells in response to cancer in the body.
Healthy people can have small amounts of CA 19-9 in their blood. High levels of CA 19-9 are often a sign of pancreatic cancer. But sometimes, high levels can indicate other types of cancer or certain noncancerous disorders, including cirrhosis and gallstones.
Because high levels of CA 19-9 can mean different things, the test is not used by itself to screen for or diagnose cancer. It can help monitor the progress of your cancer and the effectiveness of cancer treatment.
Blood typing is a method to tell what type of blood you have. Blood typing is done so you can safely donate your blood or receive a blood transfusion. It is also done to see if you have a substance called Rh factor on the surface of your red blood cells.
Your blood type is based on whether or not certain proteins are on your red blood cells. These proteins are called antigens. Your blood type (or blood group) depends on what types your parents passed down to you.
Blood is often grouped according to the ABO blood typing system. The 4 major blood types are: