Biochemistry

The human blood contains many metabolites of the body such as ions, enzymes, sugars, lipids and proteins. They play a very important role in maintaining the balance and normal function of the body's internal environment. When the body is in a disease or other abnormal physiological state, the relevant biochemical indicators in the blood will change.

Therefore, the testing of biochemical indicators such as electrolytes, total protein, enzymes and blood glucose can help clinical diagnosis, condition monitoring and efficacy assessment of diseases. This provides physicians with a basis for diagnosis and treatment. This is of great clinical importance.

The following tests are routinely performed by the Biochemistry Department, within the Department of Pathology. One or more of these tests may be ticked on your request form and they are usually performed on the day that the sample arrives in the laboratory.

• Urea and Electrolytes (U&E): The U&E may be requested as part of routine screening to check that the kidneys are functioning properly or to check a person’s electrolyte balance, articularly in patients being prescribed drugs such as diuretics or ACE inhibitors.
• Liver Function Tests (LFT): The LFT is a group of tests used to detect liver damage or disease. They may be requested to check whether drug treatment is having side effects or if symptoms of liver disease are present. These include jaundice, dark urine, diarrhoea and vomiting, stomach pains and swelling or tiredness.
• Bone profile: The bone profile is a group of tests that include the measurement of calcium and phosphate. Alterations in these levels can be associated with both bone and kidney disease.
• Cholesterol / triglycerides: Along with HDL cholesterol and LDL cholesterol, total cholesterol and triglycerides form the lipid profile. Levels of these circulating lipids provide an indication of the likelihood of having a heart attack or stroke. Also see ‘Fasting Blood Test’ information leaflet.
• High Density Lipoprotein (HDL): HDL cholesterol is often known as the good cholesterol. HDL (a combination of fats and proteins) are responsible for taking cholesterol from the cells in the body to the liver for excretion via the bile.
• Thyroid function: Testing the levels of the hormones, Thyroid Stimulating Hormone (TSH) and Thyroxine (T4) are essential in the diagnosis of thyroid disorders and in the monitoring of their treatment. The thyroid may be overactive in the case of hyperthyroidism or underactive in hypothyroidism.
• Glucose: Measuring the glucose level in the blood is a useful initial screening test for diabetes. It is also used to monitor diabetes or to confirm hypoglycaemia (low blood glucose). A single high result (hyperglycaemia) may indicate diabetes but would often need to be confirmed.