Tag Clinical chem

Blood in Urine

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.

Arterial Blood Gas

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)



Muscle twitching and/or cramps

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


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.


Pregnancy (PDT, PT)

A pregnancy test can tell whether you’re pregnant or not by detection of human chorionic gonadotropin (hCG) hormone in urine or blood.

High levels of hCG are a sign of pregnancy. hCG increases quickly in the first ten weeks after a fertilized egg attaches to the inside wall of the uterus.

Urine tests for pregnancy are most accurate when you do the test a week or two after you’ve missed your menstrual period. If you take a urine test too close to the time you got pregnant, the test could say that you are not pregnant even when you really are. That’s because your body may not yet have made enough hCG to show up on the test.

You can have an hCG urine test at your health care provider’s office or you can do the test yourself with an at-home test kit. These tests are basically the same, so many people use a home pregnancy test before calling their provider. If you follow the instructions carefully, home pregnancy tests are about 97-99% accurate. They can give you the results in minutes.

Blood tests for pregnancy can be done at your provider’s office or a lab. These tests can find very small amounts of hCG, so they can accurately show whether you’re pregnant before you’ve missed your period. But hCG blood tests aren’t commonly used to check for pregnancy.

That’s because urine tests are less expensive, very accurate, and provide quicker results than blood tests. hCG blood test results may take hours to more than a day.

Other names: human chorionic gonadotropin test, HCG test, qualitative hCG blood test, quantitative hCG blood test, Beta-hCG urine test, total chorionic gonadotropin, hCG total OB

What is it used for?

A pregnancy test is used to find out whether you’re pregnant.

Why do I need a pregnancy test?

You may need this test if you think you’re pregnant. Symptoms of pregnancy vary from person to person. The most common sign of early pregnancy is a missed period. Other common signs of early pregnancy may include:
Swollen, tender breasts
Frequent need to urinate (pee)
Nausea and vomiting (also called morning sickness)
Feeling bloated or swollen in your abdomen (belly) or body

If you need to have medical treatment that could harm an unborn baby, you may also need a pregnancy test to make sure that you aren’t pregnant.

What happens during a pregnancy test?

Home pregnancy tests are quick and easy to use. You can buy a home pregnancy test kit without a prescription. The kits include test sticks or strips that react to hCG in your urine. The steps for doing a test depend on the brand, so it’s very important to follow the instructions that come with your test.

For most test kits, you’ll either:
Hold the test stick or strip in your urine stream
Collect your urine in a cup and dip the test stick or strip into the cup
After waiting a certain number of minutes, you’ll check your results on the test stick or strip.

The instructions will tell you what to look for. In general, to get the most accurate results with any home pregnancy test, you’ll need to:
Check the expiration date before you use the test.

Test your first morning urine. Morning urine usually has more hCG than urine later in the day.
Use a timer. If you guess the timing, your results may not be accurate.

Blood tests are done at your provider’s office or a lab. 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. You may feel a little sting when the needle goes in or out. This process usually takes less than five minutes.

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

If you’re doing a urine test, don’t drink large amounts of fluid before collecting your sample. That could dilute the hCG in your urine, and it may not show up on the test.

Otherwise, you don’t need any special preparations for a pregnancy test that uses urine or blood.

What do the results means?

Your results will show whether you’re pregnant.

A negative result means hCG wasn’t found in your sample, so you may not be pregnant. But a negative result doesn’t always mean you’re not pregnant. If you did a home urine test too soon, your body may not have made enough hCG to show up the test.
hCG levels increase every day during early pregnancy, so it’s a good idea to repeat the test again in a week.

If you get negative (not pregnant) results on two home tests, but you still think you’re pregnant, call your provider. If you get a negative result on a test that your provider does, ask your provider if you need another test.

A positive result means that hCG was found in your sample. That usually means that you’re pregnant. It’s important to see your provider as soon as possible to make sure you get the right care.

If you did a home test, your provider may do another test to confirm your pregnancy.
If you’re taking medicine to help you get pregnant (fertility drugs), your test results may show that you’re pregnant when you’re not. Your provider can check to see whether you’re really pregnant.

Is there anything else I need to know about a pregnancy test?

Most pregnancy tests simply measure whether or not you have hCG in your sample. But certain pregnancy tests also measure how much hCG you have. These tests are called quantitative hCG tests, and they’re usually done on blood samples.

The amount of hCG in your body can give your provider important information about your pregnancy and the health of your unborn baby.

Quantitative hCG tests are sometimes used to help:
Find out the age of the fetus if you’re very early in your pregnancy
Monitor your pregnancy if you have a high risk of miscarriage

Check for certain problems, such as:
Ectopic pregnancy, which is a fertilized egg that tries to grow outside of the uterus. The egg cannot grow into a baby when it’s in the wrong place. It must be removed to avoid damage to your organs. This can be a medical emergency.

Molar pregnancy (hydatidiform mole), which is an abnormal growth of tissue in the uterus. It’s caused by a fertilized egg with such severe genetic problems that it cannot become a baby. The growth can turn into cancer and must be removed.

Problems in the unborn baby, including Down syndrome, other chromosome problems, and certain birth defects (hCG testing is usually part of a group of prenatal screening tests called a “triple” or “quadruple” screen test.)

Your provider may also order a quantitative hCG blood test to help diagnose or monitor health conditions that aren’t related to pregnancy. These include ovarian and testicular cancer along with other conditions that can increase hCG levels.