Category lab tests

A test called a urinalysis checks a sample of your urine (pee) to see if there’s blood in it. In some cases, you can see blood in your urine. It may make your urine red or reddish brown. But you can have small amounts of blood in your urine that you can’t see. A urinalysis can find a small amount of blood cells in your urine as well as other types of cells, chemicals, and substances.

Having blood in your urine usually isn’t serious. But in some cases, red or white blood cells in your urine may mean that you have a medical condition that needs treatment, such as a urinary tract infection (UTI), kidney disease, or liver disease.

Other names: microscopic urine analysis, microscopic examination of urine, urine test, urine analysis, UA, urine microscopy

What is it used for?

A urinalysis, which includes a test for blood in urine, is used to check your general health, including the health of your urinary tract, kidneys, and liver. The test can also be used to check for other health problems besides blood in urine.

Why do I need a blood in urine test?

Your health care provider may order a urinalysis as part of a routine exam. You may also need this test if you have seen blood in your urine or have other symptoms that could be caused by a problem with your kidneys or urinary tract. These symptoms include:

Painful urination

Frequent urination

Back pain

Abdominal (belly) pain

What happens during a blood in urine test?

You will need to give a urine sample for the test. A health care professional may give you a cleansing wipe, a small container, and instructions for how to use the “clean catch” method to collect your urine sample. It’s important to follow these instructions so that germs from your skin don’t get into the sample:

Wash your hands with soap and water and dry them.

Open the container without touching the inside.

Clean your genital area with the cleansing wipe:

For a penis, wipe the entire head (end) of the penis. If you have a foreskin, pull it back first.

For a vagina, separate the labia (the folds of skin around the vagina) and wipe the inner sides from front to back.

Urinate into the toilet for a few seconds and then stop the flow. Start urinating again, this time into the container. Don’t let the container touch your body.

Collect at least an ounce or two of urine into the container. The container should have markings to show how much urine is needed.

Finish urinating into the toilet.

Put the cap on the container and return it as instructed.

If you have hemorrhoids that bleed or are having your menstrual period, tell your provider before your test. Outside blood could get into your urine sample and affect your test results.

What do the results mean?

Many things can cause blood in urine. Most of them aren’t serious. The blood may be caused by taking certain medicines, intense exercise, sexual activity, or menstruation (having a period).

But blood in your urine may be a sign of a more serious problem, such as:

Infection in the bladder, kidney, or prostate

Bladder or kidney stones

Kidney injury from an accident or sports

A viral infection, including hepatitis(a disease of the liver causing inflammation)

Cancer of the bladder, kidney, or prostate

Enlarged prostate (BPH)

Inflammation of the kidney, urethra, or bladder

A blood disorder

Polycystic kidney disease

Disorders of the ureters(tubes that connect your kidneys to your bladder)

If your test result shows blood in your urine, you may need more tests to find out why. To learn what your results mean, talk with your provider.

Is there anything else I need to know about a blood in urine test?

A blood in urine test is usually part of a routine urinalysis. A urinalysis also measures other substances in the urine, including proteins, acid and sugar levels, cell fragments, and crystals.

Antibiotics are medicines used to fight bacterial infections. Each type of the antibiotics is only effective against certain bacteria. An antibiotic sensitivity test can help find out which antibiotic will be most effective in treating your infection.

The test can also be helpful in finding a treatment for antibiotic-resistant infections. Antibiotic resistance happens when standard antibiotics become less effective or ineffective against certain bacteria. Antibiotic resistance can turn once easily treatable diseases into serious, even life-threatening illnesses.

Other names: antibiotic susceptibility test, sensitivity testing, antimicrobial susceptibility test

What is it used for?

An antibiotic sensitivity test is used to help find the best treatment for a bacterial infection.

Why do I need an antibiotic sensitivity test?

You may need this test if you have an infection that has been shown to have antibiotic resistance or is otherwise hard to treat. These include tuberculosis, MRSA, and C. diff. You may also need this test if you have a bacterial or fungal infection that is not responding to standard treatments.

What happens during an antibiotic sensitivity test?

The test is done by taking a sample from the infected site. The most common types of tests are listed below.

Blood culture

A health care professional will take a blood sample from a vein in your arm, using a small needle. After the needle is inserted, a small amount of blood will be collected into a test tube or vial.

Urine culture

You will provide a sterile sample of urine in a cup, as instructed by your health care provider.

Wound culture

Your health care provider will use a special swab to collect a sample from the site of your wound.

Sputum culture

You may be asked to cough up sputum into a special cup, or a special swab may be used to take a sample from your nose.

Throat culture

Your health care provider will insert a special swab into your mouth to take a sample from the back of the throat and tonsils.

Are there any risks to the test?

There is very little risk to having a blood culture test. You may have slight pain or bruising at the spot where the needle was put in, but most symptoms go away quickly.

There is no risk to having a throat culture, but it may cause slight discomfort or gagging.

There is no risk to having a urine, sputum, or wound culture.

What do the results mean?

Results are usually described in one of the following ways:

The tested medicine stopped the growth or killed the bacteria or fungus causing your infection. The medicine may be a good choice for treatment.

The medicine may work at a higher dose.

The medicine did not stop the growth or kill the bacteria or fungus causing the infection. It would not be a good choice for treatment.

If you have questions about your results, talk to your health care provider.

Is there anything else I need to know about an antibiotic sensitivity test?

Incorrect use of antibiotics has played a big role in the rise in antibiotic resistance. Make sure you use antibiotics the right way by:

Taking all doses as prescribed by your provider

Only taking antibiotics for bacterial infections. They don’t work on viruses, like colds and flu.

This test measures the amount of oxygen and carbon dioxide in your blood. It also checks the acidity of your blood. This is called your acid-base balance or your pH level. The blood sample is taken from an artery, which is a blood vessel that carries oxygen-rich blood from your lungs to your body.

In an ABG test, the blood oxygen measurement shows how well your lungs move oxygen from the air into your blood when you breath in. The carbon dioxide measurement shows and how well your lungs remove carbon dioxide from your blood when you breath out.

Carbon dioxide is an acidic waste product that your body makes. If your blood and tissues become even slightly too acidic or too basic (alkaline), it can seriously affect many of your organs and even become life-threatening.

Your lungs and your kidneys do much of the work to keep your acid-base balance normal. So, the acid-base measurement from an ABG test can help diagnose and monitor conditions that affect your lungs and kidnesys as well as many other conditions that may upset your acid-base balance.

Other names: blood gas test, arterial blood gases, ABG, , oxygen saturation test

What is it used for?

An ABG test is used to help:

Check your acid-base balance

Diagnose serious problems with your lungs and breathing

Diagnose kidney disorders

Find out whether treatment is working for breathing disorders, kidney disease, or other conditions that may affect your acid-base balance

Why do I need an arterial blood gas (ABG) test?

There are many reasons why you may need this test. For example, you may need an ABG test if you:

Have symptoms of a problem with your acid-base balance, such as:

Uncontrolled rapid or deep breathing, which may be a sign that your lungs are trying to adjust acids or bases by changing the amount of oxygen or carbon dioxide in your blood

Nausea and vomiting

Arrhythmia(a problem with the rate or rhythm of your heartbeat)

Confusion

Fatigue

Muscle twitching and/or cramps

Are being treated for a lung disease or a condition that affects your breathing, such as:

Asthma

Chronic obstructive pulmonary disease (COPD)

Cystic fibrosis

Myasthenia gravis

Have symptoms after you have had:

Carbon monoxide poisoning

An inhalation injury(breathing in smoke, hot air, and/or harmful chemicals)

A recent heador neck injury that could affect your breathing

Are receiving oxygen therapyin the hospital

What happens during a blood oxygen level test?

Most blood tests take a sample from a vein. For this test, a health care provider will take a sample of blood from an artery. That’s because blood from an artery has higher oxygen levels than blood from a vein.

The sample is usually taken from an artery on the inside of your wrist, but it may be taken from an artery in your arm or groin. For a newborn, the sample may be taken from the baby’s heel or the umbilical cord shortly after birth.

If your blood sample is taken from your wrist, the provider will first test your blood circulation. The provider will hold your wrist and apply pressure to the arteries to cut off blood flow to your hand for several seconds. Then the provider will let go of your wrist to check how quickly blood flow returns to your hand. If your blood flow is normal, the provider will collect a blood sample.

A blood sample taken from an artery tends to be more uncomfortable than most blood tests, which use a vein. So, the provider may apply some numbing medicine to your skin first. The provider will insert a needle with a syringe into the artery to remove some blood.

When the syringe is full, the provider will bandage the puncture site. Pressure will be applied to the site for at least 5 minutes to stop the bleeding.

Will I need to do anything to prepare for the test?

If you take blood thinners, including aspirin, ask your health care provider whether you should stop taking them before your test. And tell your provider about all other medicines and supplements you take. But don’t stop taking any medicines unless your provider tells you to.

If you are on oxygen therapy, your oxygen may be turned off for about 20 minutes before the test. This will be done only if you can breathe without oxygen therapy.

What do the results mean?

ABG test results involve many body systems that affect each other. And there are many health conditions that can cause abnormal results. For these reasons, it’s best to have your provider explain what your results mean for your health.

Your ABG test results will list many measurements, including:

Oxygen saturation (O2Sat).This measures how much oxygen your red blood cells are carrying

Partial pressure of oxygen (PaO2).This measures the pressure of oxygen that’s dissolved in your blood. It helps show how well oxygen moves from your lungs to your bloodstream.

Partial pressure of carbon dioxide (PaCO2).This measures the amount of carbon dioxide in your blood. It also shows how easily carbon dioxide can move out of your body.

Acid-base balance (pH level).This measures the acidity of your blood. Too much acid is called acidosis. Too much base (alkaline) is called alkalosis. These conditions are symptoms of other problems that upset the acid-base balance in your body.

An ABG test alone usually can’t provide a final diagnosis. So, if your results are not normal, your provider will likely order more tests to make a diagnosis. In general, abnormal results may mean you have a problem with your lungs or kidneys or a metabolic disorder. Metabolic disorders affect how your body uses food for energy. Certain medicines may also upset your acid-base balance and lead to abnormal ABG test results.

Is there anything else I need to know about blood oxygen level tests?

Another type of test, called pulse oximetry, can check your blood oxygen saturation levels. A small clip-like device, called a pulse oximeter, is usually attached to your finger. The device tells you the percentage of red blood cells that are full of oxygen. Pulse oximetry may be useful if blood oxygen levels are the only concern. Ask your provider if this test is right for you.