What is a blood test?

Blood tests are one of the most common tests and allow, via a simple venipuncture, to check the values of the main blood components and thus provide important information on the patient’s health and function of their body. The doctor may prescribe different types of examinations according to the requirements of the patient and depending on what it is necessary to investigate. Some of the tests are considered routine and are used to identify levels of the following:

  • Glucose
  • Creatinine
  • Homocysteine
  • BUN (blood urea nitrogen test)
  • Sodium
  • Potassium
  • Calcium
  • Aspartate aminotransferase (AST)
  • Alanine aminotransferase (ALT)
  • Lactate dehydrogenase (LDH)
  • Creatine phosphokinase (CPK)
  • Gamma glutamyl transpeptidase (GGT)
  • Amylase
  • Triglycerides
  • Total cholesterol
  • HDL cholesterol
  • Bilirubin
  • Iron
  • Uric acid
  • Blood count


Why undergo a blood test?

Blood tests allow us to identify substances that circulate in the body, and hence check the functioning of the many vital organs. The results are then shared with your doctor or specialist who prescribed them, they will then proceed to the correct readings, giving them a proper weight and possibly placing them in a diagnostic path.


Standard of preparation

The sampling is performed in the morning, when you visit the hospital, preferably before nine o’clock. The doctor will advise and recommend if you need to be fasting prior to the blood examination. In this case it is recommended that the patient does fast prior to the exam, and arrives with an empty stomach. You should inform your doctor of any medication you are taking prior to the exam, as some medical treatments may interfere with the blood results.


Who can undergo this examination?

Any patient may undergo the examination, depending on what specifically is being tested, or required by either the doctor or patient in question.

Is the exam painful or dangerous?

The examination is not dangerous and is not painful, you may feel a tingling sensation when the needle enters the arm of the body. Many people, however, appear uneasy about this kind of examination and generally prefer not to watch the maneuvers of the nurse. The withdrawal is resolved in a few minutes so, if the idea of drawing blood arouse impression, you should try to distract yourself.


How is the exam performed?

Blood tests are performed by venipuncture, preferably between seven and nine in the morning. The patient, who should be fasting prior to the examination, should wait in the office for a few minutes and eventually the operator comes to explain the process in simple steps. The nurse disinfects the part where the needle will be inserted in the forearm, then goes on to apply the tourniquet, asking the patient to close their fist and once the vein is identified needle slips into the vein. At this point the patient re-opens the hand, the tourniquet is released and the sampling is completed, removing the needle and transferring blood into one or more tubes depending on the type of tests required. A withdrawal is completed, the affected part of the body is applied with cotton ball and a strip of medical tape that the patient is asked to keep for ten minutes, to ensure that bleeding does not resume. The results are typically available in a short time: from a few days to a week.