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If you have particular symptoms or are unwell, then your doctor might request additional tests to try and find out the cause. Some of the more common of these are described here.


On occasion you may be asked to provide a urine, stool or sputum sample. These will be looked at in a laboratory to see if there are any infections or other abnormalities.

X-rays, scans and ultrasounds

These are generally painless, non-invasive ways of seeing different parts of the body.

X-rays have a number of uses and are often used to check for broken bones or problems within the chest or abdominal cavities.

Looking at an X-ray can help your doctor diagnose a number of illnesses. Chest X-rays are quite a common procedure used to look at the heart, lungs and chest wall. They can help diagnose the cause of various symptoms, such as coughs or shortness of breath. Your doctor may ask you to have a chest X-ray if they suspect you have a chest infection or tuberculosis (TB).

Sometimes your doctor may recommend a scan. There are two main types of scan:

  • a CT (computerised tomography) scan, sometimes called a CAT scan, and  
  • an MRI (magnetic resonance imaging) scan.

CT scans allow a more detailed view of lots of different tissue types in the body, including lungs, bones, soft tissues and blood vessels.

MRI scans can be used to diagnose health conditions that affect organs, tissue and bone. An MRI scan can be used to investigate almost any part of the body. It can look at the brain and spinal cord, bones and joints, the heart and blood vessels, and internal organs, such as the lungs and liver, amongst other things.

MRI scans are sometimes used to look at HIV’s effects on the brain and changes in body fat distribution. If you are having an MRI scan, you may be given a liquid called a ‘contrast agent’ (either by drinking it or having it via an intravenous drip), that highlights specific areas of the body in the scan.

Another type of scan is a DEXA (dual X-ray absorptiometry) scan. It is useful for diagnosing thinning bones and for looking for the fat loss that some older anti-HIV drugs can cause.

An ultrasound uses high frequency sound waves to create an image of part of the inside of the body. It is used most often to examine the chest or stomach area. It involves having an instrument placed against the surface of the abdomen and moved around the area. It is used to check on the development of a baby in the womb and can also be used to help diagnose problems with organs such as the heart, liver, stomach, kidneys, pancreas and spleen.

A specialised type of ultrasound scan can be used to check the health of the liver. It is called elastography and involves having an instrument placed against the abdomen over the liver.

Other procedures

If your doctor feels they need more information to diagnose or treat a health problem you have, they may recommend that you have other procedures done. Some of these can be a bit more invasive, but generally don’t involve surgical procedures or need you to stay in hospital. They are usually carried out during an outpatient appointment and you can go home afterwards.

If you are offered a sedative, you may have to wait at the hospital a bit longer before you can leave. You will be advised not to drive, nor to go back to work that day. You may need to have someone to take you home and stay with you for some hours after the procedure.


This can be used to investigate chest problems. Your doctor may suggest this if you have a cough, are short of breath, or have had an abnormal chest X-ray.

It involves the use of a bronchoscope – a flexible tube that has a light and camera on it and allows a doctor to look at your bronchial tree (breathing tubes) and lungs.

Before you have a bronchoscopy, you’ll be offered some sedation, such as diazepam (Valium), and have a local anaesthetic sprayed onto the back of your throat. The bronchoscope is then passed through a nostril and down into the lungs. Fluid is washed down to obtain samples that can be used to diagnose lung infections such as TB or pneumonia.

A small sample of tissue (a biopsy) may also be removed during the procedure, for examination in a laboratory.


An endoscope is also a tube with a light and a camera attached. It is used to look at different parts of the body. It is normally put in through an opening such as the mouth or the anus.

The most common use for an endoscope is to do a gastroscopy, used to investigate problems with the gullet (the food pipe in the throat), stomach or bowel. Your doctor might recommend a gastroscopy if you often have indigestion or heartburn, vomiting, stomach pain or difficulty swallowing.

The endoscope is passed through the mouth, down the gullet and into the stomach.

It is important not to eat or drink for some hours before this procedure as the stomach has to be empty. You will be told how long to fast for.

You will be given the choice of a sedative before the procedure, a local anaesthetic spray, or both. The procedure is generally painless but might be uncomfortable at the moment you swallow the tube.


This test can be used to investigate problems in your colon, or large intestine (bowel), such as bad diarrhoea or bleeding.

It involves the use of a colonoscope. This is a thin flexible instrument with a light and a camera on it that allows a doctor to look at the rectum and colon. It can also be used to take tissue samples (biopsies) that can be examined in a laboratory.

You may need to be on a particular diet for a day or two beforehand, or you may be asked not to eat anything for some hours. You’ll be asked to take a laxative before the procedure. The colonoscope is passed up through the anus into the rectum and into the colon. It is not painful, although some people find it uncomfortable. You will usually be given a sedative to help you relax.


A biopsy can help diagnose some symptoms or illnesses if the procedures described above are not adequate. A biopsy involves having a small amount of tissue removed that is then examined in a laboratory.

Sometimes a biopsy is taken when having another investigation, for example, a bronchoscopy or endoscopy. At other times, it will be taken by using a hypodermic needle, or it will be necessary to have a small surgical procedure after having a local anaesthetic.

Biopsies can be done on a wide range of organs, including the skin, the liver, kidneys, bone marrow, the intestines, the rectum and the cervix.


CD4, viral load & other tests

Published February 2017

Last reviewed February 2017

Next review February 2020

Contact NAM to find out more about the scientific research and information used to produce this booklet.

This content was checked for accuracy at the time it was written. It may have been superseded by more recent developments. NAM recommends checking whether this is the most current information when making decisions that may affect your health.
Community Consensus Statement on Access to HIV Treatment and its Use for Prevention

Together, we can make it happen

We can end HIV soon if people have equal access to HIV drugs as treatment and as PrEP, and have free choice over whether to take them.

Launched today, the Community Consensus Statement is a basic set of principles aimed at making sure that happens.

The Community Consensus Statement is a joint initiative of AVAC, EATG, MSMGF, GNP+, HIV i-Base, the International HIV/AIDS Alliance, ITPC and NAM/aidsmap

This content was checked for accuracy at the time it was written. It may have been superseded by more recent developments. NAM recommends checking whether this is the most current information when making decisions that may affect your health.

NAM’s information is intended to support, rather than replace, consultation with a healthcare professional. Talk to your doctor or another member of your healthcare team for advice tailored to your situation.