Pathology, according to The Royal College of Pathologists is; “the hidden science that every day saves lives by helping doctors to make the right decisions.”
As Dr Nigel Kellow points out in his excellent ‘Pain Management’ article, there are laboratory tests for pretty well every known substance in the body. These substances are normally either supposed to be present, or depending on amount mark a certain pathological (disease) state. As a result, laboratory testing combined with symptoms is the traditional first step to making a medical diagnosis.
Historically, due to the technical complexity of the tests themselves and the need to understand what is and isn’t ‘normal’, these tests have been the strict domain of doctors to control and request on behalf of their patients. However, this situation is now changing. For example, there are government initiatives to encourage people to come forward to be tested for HIV and / or Chlamydia. Why? - Because a rapid diagnosis will allow you to be treated quickly and help prevent further spread of the disease.
Even ten years ago, many of these tests were laborious and time consuming to perform in specialist laboratories, but the technology has now changed to the extent that many pharmacies now sell self-testing kits - anything from pregnancy testing through to cholesterol. It is still relatively early days and there are sometimes problems associated with these kits. It is therefore still generally recommended to be tested professionally using an accredited laboratory.
The technology is improving rapidly and soon everyone will be able to place something as simple as a saliva sample on a test strip that feeds into an accessory on a PC. Add in information on your symptoms and family history and the technology will almost remove the need for a doctor. However, we are not there yet and different tests require different types of sample, for example:
- Biochemistry tests (e.g. Cholesterol, sodium, potassium etc) – requires coagulated blood
- Haematology tests (e.g. haemoglobin, white blood cells) – requires whole blood
- Microbiology tests (e.g. strep sore throat) – may require a swab
- Virology tests (e.g. hepatitis, measles, HIV) – may require saliva or a blood sample.
There is practically nothing you cannot be tested for.
In a new era of ‘patient choice’ you can either test yourself using a kit from the pharmacy, or you can send a sample to the laboratory to have a full set of profiles, and you can have anything tested from nutritional and vitamin levels, allergy markers, auto-immune disease, rare disorders, hormones, drugs to tumour markers. There is a test for pretty well everything.
You can check either your status at any one point in time, or you can monitor change over time. For example, you can check to see if the antiviral drugs are working or you might want to see if a healthier lifestyle is actually improving your lipid levels.
So why are we not testing ourselves?
The prime reason is cost. The price of a single test can vary from a penny to hundreds of pounds. There are other reasons too ranging from trying to determine an abnormal result against a ‘normal range’ through to the more psychological implications.
Normal Range
With all the publicity and advertising around healthy diets, if you were to ask someone – is cholesterol good for you? You might be surprised by the range of answers you get. Of course, cholesterol is pretty essential for life, but elevated cholesterol levels could indicate an underlying disease state (depending on the type of cholesterol – HDL and LDL). If you measure cholesterol in a thousand people you can produce a statistical range and find the average, from this you can find the ‘normal range’. However, this is a slightly precarious assumption, because what is ‘normal’ in one person may not be for another. Therefore, ‘normal ranges’ can only really be used for guidance and comparison.
Psychological Implications
The implications are potentially far reaching. Discovering you are pregnant could either be an absolute joy, or a concern. Equally, professional counselling is strongly advised in association with some tests, such as HIV.
But the point is that if you want to be tested for anything – you can, and knowing your own profile (even if it is just blood type) and understanding some basic pathology is fundamental to understanding the state of your own health.
