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Pathology services

What is pathology?

Unlike the pathologists you might see on the television, those working in the NHS are more likely to work for the benefit of the living, rather than spending all day with dead bodies, performing post-mortems or investigating murders.

Pathology is the study of disease, its causes and progression. Nearly every patient in the NHS has had dealings with pathology services at some point. Every time you give a blood, stool, urine or tissue sample, it is analysed by a pathologist or pathology scientist, known as a biomedical or clinical scientist, depending on their skills and qualifications.

Pathologists look for abnormalities within samples but, quite often, these tests are performed to confirm everything is OK. Through preventative screenings, tests can help with the early detection of potentially fatal conditions.

Pathology also plays a major role in research, such as finding treatments for cancer and inherited conditions, developing vaccines against infectious diseases or ensuring that blood transfusions are safe.

This is why there are many different specialist areas in pathology, such as forensic pathology, which looks at the causes of death. The four main specialties in pathology are:

  • chemical pathology – the study of chemicals in the blood and other fluids
  • haematology – the study of disorders of the blood
  • histopathology – the study of disease in human tissue
  • medical microbiology – the study of infection

Visit the Royal College of Pathologists website for more details about the different pathology specialties. 


What are pathology tests used for?

Pathology is central to most areas of healthcare, providing insights into how to manage patients' conditions, either by confirming a diagnosis, managing medication or monitoring the progression of a condition. To find out more about pathology tests and why they're performed, visit the Lab Tests Online UK website.

Screening for disease

The aim of screening is to pick up a disease in the early stages so it can be treated or prevented before the person is even aware they have it, or before it develops into something more serious.

Screening is used for various reasons. It can help with the early detection of conditions such as cancer, or help determine the chances of carrying inherited or genetic diseases, such as Creutzfeldt-Jakob disease or Down's syndrome.

Read about some of the national screening programmes available:

Screening is also used for people who work with hazardous materials, such as mercury, lead or asbestos, or after industrial accidents.

Checking for potential health risks

These are common health checks to determine your risk of developing diseases, such as diabetes. For example, you may have a blood test to determine the cholesterol levels in your blood.

The results of this test are used in combination with information about your blood pressure, weight and lifestyle habits, such as smoking or drinking, to determine your risk of heart disease or stroke.

Diagnosing a condition

Diagnosing an illness isn't always straightforward. Some conditions, such as tropical diseases, have similar symptoms, and others are determined by hormone levels or concentrations of other chemicals in the blood. If this is the case, your GP will arrange for simple tests to help with the diagnosis and appropriate treatment.

Giving a prognosis of an illness

If you're unwell, you need your doctor to be able to tell you how long it will take until you feel better. For serious conditions like cancer, it's important to determine what stage the cancer has reached to give an indication of severity, treatment choices and, in cases of a terminal disease, the most appropriate palliative care.


Pathology tests can help your doctor monitor the progression of a condition and determine whether it's getting better or worse. For example, thyroiditis is inflammation of the thyroid gland that can either cause abnormally low or high levels of thyroid hormones in the blood.

Your doctor may order regular blood tests to determine whether the inflammation has eased or is getting worse, and will use this information to decide which course of treatment you should have.

Another reason is to monitor drug levels in your blood. Some prescription drugs can cause toxic symptoms when the concentration in the blood is very high, or they don't have any effect if the levels are too low. It's therefore necessary to perform regular tests to measure the concentration of the drug in your blood.

Medication also needs to be monitored because drugs can have serious side effects. For example, drugs given after certain organ transplants can affect kidney or liver function. Transplant patients are therefore monitored regularly to avoid serious damage to otherwise healthy organs.  

What happens to my samples?

In most cases, you'll have your sample taken at a hospital or your GP surgery. The doctor or nurse will then pass it on to the lab and it will be processed from there.

Samples sometimes have to be sent to more than one speciality lab. How the sample is stored depends on the type – some samples need to be kept frozen at all times, some need to be delivered within the hour or in special containers if there is a risk of infection, and others can be sent by post.

You can always check with your doctor to find out more about how your sample reaches a pathology laboratory.

If you have to hand in a sample – such as a stool, urine or semen sample – yourself, you should always follow the instructions given to you in advance. This will ensure your test results are as reliable as possible and will avoid having to take samples again. This includes instructions about any changes to your diet. For example, if you have to hand in a semen sample, it should be kept warm, and you are often asked to fast before a blood test for diabetes.

Always make sure to label any specimen container with:

  • your first name
  • your last name
  • your date of birth
  • your reference or hospital number (if you have one)
  • what the specimen is (urine, faeces, semen)
  • the date and time the specimen was taken

Also read advice on:

As soon as your specimen arrives in pathology, it is assigned a pathology number so laboratory staff can keep track of it. This also allows your tests to remain anonymous.

How your sample is handled by pathologists and scientists depends on the sample and the type of tests being done. Not all pathology laboratories process specimens in the same way or within the same time period.

You could always ask your doctor where the samples are sent. Most hospitals that have a pathology department also have a section on their website to explain their services, and they also provide contact details in case you have any questions.

How long does it take to get my results?

This depends on the type of test that needs to be done. More than 90% of samples arriving at biochemistry and haematology labs will be reported on the same day. There is a very high use of automation and robotics within these specialities.

Other samples require more time and resources, such as when tissue needs to be examined under the microscope. This can take several days, depending on the tests that need to be done, the availability of scientist and pathologist staff, and the workload of the histopathology department.

Similarly, if a sample needs to be cultured (growing bacteria in petri dishes), a result cannot be reported until the culture has had time to grow and be identified.

Other reasons why you may have to wait longer for your results:

  • the sheer complexity of the test requires considerable tie.
  • samples for that type of test are received less frequently and are stored so they can be analysed in a batch, for both quality and economic reasons.
  • the test needs to be sent on to a highly specialised laboratory.

Sometimes you may find it takes a long time before you get your results. This is not always because the lab needed a long time to analyse your samples – it could be that your GP needs time to put the test results into the context of your medical history. Pathology test results are often complex and need skilled interpretation. Your doctor may discuss the results with the pathologist, scientist or other healthcare professional before coming to a conclusion. Your doctor also needs to find a way to explain this to you in simple terms.

If you are seeing a consultant at the hospital, they may have arranged to discuss the results at your next visit. Your doctor wouldn't necessarily contact you beforehand unless there is a medical reason to do so.

How do I know my lab gives the right answers?

Pathology laboratories make considerable efforts to ensure their results are correct. Like other industries, they undertake quality control measures and compare their results internally and with other laboratories undertaking the same type of test.

This latter process is called external quality assurance (EQA). Most EQA is organised on a national basis, so laboratories can compare their results with others' – up to about 200 for some tests – and with laboratories using the same test methods and equipment.

If a laboratory performs poorly, the EQA process includes contacting the laboratory, identifying the problem and helping them overcome any problems. If this doesn't lead to improvements, the organiser will report the matter to the Royal College of Pathologists for them to take action.

How are pathology labs regulated?

The system of Clinical Pathology Accreditation is run by the UK Accreditation Service (UKAS) and inspects laboratories on a regular basis. This is a very thorough review of the processes in each pathology discipline undertaken by that laboratory and is done to international standards (ISO 15189 medical laboratories). This approach applies to all laboratories, whether they are part of the NHS or private.

Further information

The NHS England Pathology Programme is constantly trying to improve pathology services for patients and staff in the delivery of efficient, effective and safe services. For more information, download Digital First: clinical transformation through pathology innovation (PDF, 1.71Mb).

Page last reviewed: 22/03/2016

Next review due: 22/03/2019

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