The blood is a window into the health of the body. It is important to understand that blood testing is not meant to be a substitute for a professional medical diagnosis. However, when done properly and analysed accurately, blood testing can help you identify potential health problems, seek appropriate medical advice, and make positive changes in your lifestyle.
Blood tests help doctors check for certain diseases and conditions and prevent them early. They also help check the function of your organs and show how well treatments are working. Specifically, blood tests can help to:
- Assess your general state of health
- Check if you have an infection
- See how well certain organs, such as the liver and kidneys, are working
- Screen for certain genetic conditions
Preparing for a blood test
The healthcare professional who arranges your blood test will tell you whether there are any specific instructions you need to follow before your test.
For example, depending on the type of blood test, you may be asked to:
- Avoid eating or drinking anything, apart from water for up to 12 hours
- Stop taking a certain medication
It’s important to follow the instructions you’re given, as it may affect the result of the test and mean it needs to be delayed or carried out again.
What happens during a blood test?
A blood test usually involves taking a blood sample from a blood vessel in your arm.
The arm is a convenient part of the body to use because it can be easily uncovered. The usual place for a sample to be taken from is the inside of the elbow or wrist, where the veins are relatively close to the surface.
Before taking the sample, the doctor or nurse may clean the area of skin with an antiseptic wipe.
A needle attached to a syringe or special container is inserted into the vein. The syringe is used to draw out a sample of your blood. You may feel a slight pricking or scratching sensation as the needle goes in, but it shouldn’t be painful. If you don’t like needles and blood, tell the person who is taking the sample so they can make you more comfortable.
After the test
Only a small amount of blood is taken during the test so you shouldn’t feel any significant after-effects.
However, some people feel dizzy and faint during and after the test. If this has happened to you in the past, tell the person carrying out the test so they’re aware and can help you feel more comfortable.
After the test, you may have a small bruise where the needle went in. Bruises can be painful but are usually harmless and fade over the next few days.
What does a full blood count involve?
A complete blood count (CBC) is a blood test used to evaluate your overall health and detect a wide range of disorders, including anaemia, infection and leukaemia. A complete blood count test measures several components and features of your blood, including:
- Red blood cells, which carry oxygen
- White blood cells, which fight infection
- Haemoglobin, the oxygen-carrying protein in red blood cells
- Haematocrit, the proportion of red blood cells to the fluid component, or plasma, in your blood
- Platelets, which help with blood clotting
Abnormal increases or decreases in cell counts as revealed in a complete blood count may indicate that you have an underlying medical condition that calls for further evaluation.
Why it’s done
A complete blood count is a common blood test that’s done for a variety of reasons:
- To review your overall health. Your doctor may recommend a complete blood count as part of a routine medical examination to monitor your general health and to screen for a variety of disorders, such as anaemia or leukaemia.
- To diagnose a medical condition. Your doctor may suggest a complete blood count if you’re experiencing weakness, fatigue, fever, inflammation, bruising or bleeding. A complete blood count may help diagnose the cause of these signs and symptoms. If your doctor suspects you have an infection, the test can also help confirm that diagnosis.
- To monitor a medical condition. If you’ve been diagnosed with a blood disorder that affects blood cell counts, your doctor may use complete blood counts to monitor your condition.
- To monitor medical treatment. A complete blood count may be used to monitor your health if you’re taking medications that may affect blood cell counts.
At Pall Mall, We offer accredited pathology services, giving you access to over 1500 laboratory tests you can choose from without restriction. This means you can get the tests you want, whether a single test or multiple tests and all results are fully confidential. Click here for more information or call us on 03300 58 44 55.