Having a blood test 

Blood tests are a very useful diagnostic tool. Blood is made up of several different kinds of cells and other compounds, including various salts and certain proteins. 

Blood contains two main elements: the fluid that is called plasma and cells. There are three kinds of cells: red blood cells, white blood cells and platelets.

Why do we need to take blood?

Blood tests are carried out to help in the diagnosis, care and treatment of various health conditions and diseases. They may be requested by doctors, nurses and other healthcare professionals. 

What am I being tested for?

The clinician caring for you can tell you this. Further information can be obtained from ww.labtestsonline.org.uk w

Where can I have it done?

• North Colchester Healthcare Centre
• hospital-based blood clinics
• at your GP surgery (please check availability)
• maternity services (01206 742403). 

How long will the blood test take?

The clinics work on a first come, first served basis. At busy times this can mean that you may be waiting some time. 

What can I do to help myself?

• If attending the North Colchester Healthcare Centre or one of the hospital blood clinics please ensure:
• you have blood request/authorisation forms from your GP. Please check that all forms contain your name and date of birth, that there are ticks to indicate the tests you need to have and it has been signed by your GP. If any information is missing, please check with your surgery before attending the blood clinic
• you are wearing suitable clothing, as you will need to bare your arm to above the elbow. The procedure takes a few minutes and normally causes minimal discomfort. Please let staff know if you have any particular concerns
• after the blood test, you refrain from carrying heavy items or undertaking exercise in order to reduce the likelihood of bruising. Slight bruising is not unusual. However, if the bruising is extensive and painful, please contact the relevant blood clinic, GP surgery or NHS Direct. 

Fasting blood tests

Some tests require you to fast before the blood is taken. This means not eating or drinking anything, other than water, after 10pm the night before the test. Your GP or practice nurse should tell you if you need to fast and this may also be written on the form that was given to you for the blood test.

The most common tests where fasting may be required are glucose (diabetes), triglyceride and HDL (done with cholesterol). Please note that testing for cholesterol on its own does not require fasting. If you have fasted, tell reception staff when you arrive. 

Services for children

Discuss with your doctor because a prescription for anaesthetic cream can be provided. This will be applied to the child's arm 40 minutes before the blood test and you will need to allow time for this. The North Colchester Healthcare Centre cannot perform blood tests for children aged 12 years or under. Colchester General Hospital blood clinic will take children three years and over if they have been provided with the anaesthetic cream or do not require its use. The Children's Day Unit also has an appointment system for babies and young children.

Special tests

There are a few tests that are more complex and require you to make an appointment by ringing the blood clinic at Colchester General Hospital on 01206 742416. Your doctor will tell you if this is necessary and provide all the relevant information.