Success of a medical treatment is dependent on correct diagnosis of the disease. Medical tests are used to detect abnormalities or presence of a health condition in a human body along with the degree of illness. Proper diagnostic processes are therefore critical to treatment and recovery from the disease. Given below are the diagnostic tests commonly used in a hospital environment.
Medical Diagnostic Tests
Complete blood count( CBC ) or full blood count is a very common type of blood test which is an analysis of 15 different blood test readings that gives an overall picture of a person’s health. CBC is generally the initial test prescribed by the doctor to gauge if the patient has got an infection, if the patient is anemic or if there could be other reasons that is causing patients’ symptoms.
Human blood consists of three types of cells — white blood cells (leukocytes), red blood cells( erythrocytes), and platelets( thrombocytes). Abnormally high or low counts may be indicative of some diseases. CBC is therefore performed in every routine health check up.
Symptoms and conditions that require CBC tests for correct diagnosis -
- Fatigue, weight loss, fever, bruising, etc. for a length of time.
- Too much bleeding. For example, over-bleeding during menstruation period in women.
- Suspected infection.
- Suspected blood cancer, such as leukemia.
- Suspected conditions like asthma, and allergies.
- Essential blood test before any surgeries.
- As routine blood test on the cancer patients subjected to radiation and chemotherapy to ensure that the therapies are not affecting the blood cells negatively.
The comprehensive metabolic panel ( CMP ) comprises of 14 different blood tests that gives the current status of a person’s metabolism. It gives information about kidney function, liver function, levels of electrolytes, acid/base balance, level of blood glucose and blood proteins.
A CMP is done to learn information about the levels of :
- Glucose: The main source of energy in the body. There should be a relatively constant level of glucose in the blood. High glucose percentage in blood points to diabetes.
- Calcium: An essential mineral for proper functioning of muscles, nerves, and the heart. Also important for blood clotting and formation of bones.
- Electrolytes: Electrolytes are ionised solutions that can conduct electricity. Our body has electrolytes that generate electricity, contract muscles, move water and fluids within the body. Normal levels of electrolytes maintains proper functioning of cells and organs in our body. Our body electrolysis include -
- Sodium: Important for normal functioning of the body, including muscles and nerves.
- Potassium: Important for cell metabolism and muscle
- CO2: Important for maintaining body’s acid base balance.
- Chloride: Works with Sodium and Potassium to control body’s fluid levels and maintain its acid-base balance.
- Blood urea nitrogen (BUN) and creatinine: Levels of creatinine and BUN are indicators of kidney function, as they are the waste substances filtered from the blood by the kidneys.
- Albumin and globulin: These are called the total proteins which are essential for building and maintaining muscles, bones, blood, and organ tissues. Protein Deficiencies lead to malnutrition and liver, and kidney problems.
- Alkaline phosphatase (ALP), alanine aminotransferase (ALT), and aspartate aminotransferase (AST): High levels of these enzymes in the liver indicate some problems with liver.
- Bilirubin- Bilirubin is a yellow colored compound excreted in bile and urine, formed due to breakdown of red blood cells(hemoglobin). Higher level of Bilirubin indicates liver problems.
3. EKG and Cardiac Enzyme Analysis:
Electrocardiogram (ECG or EKG) is a test that indicates heart conditions. The ECG machine converts electrical signals from the heart onto a paper. The pattern of these signals provides information to the doctors whether the heart is okay or not, or under stress, or passing through strain or other electrical problems.
4. Flu screening:
Influenza(Flu) is a general viral respiratory infection that results in mild to severe illnesses. A flu test is performed to determine if somebody has got influenza infection, especially if she/he is hospitalized, or can catch flu due to feeble immune system or there is a chance of spreading flu in the community. Two types of influenza viruses, A and B, cause pandemics while type C causes mild respiratory illness.
5. Liver Panel:
A liver panel is a group of tests that are carried out together to detect, examine, and monitor liver diseases. Liver is the largest organ in the human body responsible for
1) Filtering blood coming from the digestive tract before passing it to the rest of the body.
2) Detoxifying chemicals and metabolizing drugs.
Tests for different types of liver disease:
When diagnosing liver disease the most useful test in each disease is often (but not always) as shown in the table below
- Alcohol related liver disease: History/liver function tests (blood sample)
- Autoimmune hepatitis: Autoantibodies such as anti-nuclear antibody and anti-smooth muscle antibody (blood sample)
- Haemochromatosis: HFE Gene analysis for C282Y or H63D mutation (blood sample)
- Hepatitis A: Antibody test (blood sample)
- Hepatitis B: Antibody, antigen tests/hepatitis B DNA (blood sample)
- Hepatitis C: Antibody test/hepatitis C RNA (blood sample)
- Fatty liver disease, non alcoholic fatty liverdisease (NAFLD), non alcoholicsteatohepatitis (NASH): History/liver function tests (blood sample)/ BMI/ultrasound scan appearance and liver biopsy
- Primary biliary cirrhosis: Anti-mitochondrial antibody (blood sample)
- Primary sclerosing cholangitis: Biopsy/bile duct imaging – ERCP
- Wilson’s disease: Genetic analysis/copper studies (blood and urine samples), slit lamp examination of the eyes.
Often a liver biopsy is required to confirm the diagnosis. The need for this will be guided by your doctor or liver specialist.
6. Pregnancy test:
Pregnancy is detected if the urine or blood of a woman contains a hormone called chorionic gonadotropin(hCG). Blood tests give faster results than the urine tests.
Blood test to detect pregnancy- There are two types of blood tests, any one of which can be performed to confirm pregnancy-
Qualitative HCG Blood test — This confirms presence or absence of HCG hormone. hCG levels of 25 mIU/mL and more is usually detected by this method.
Quantitative HCG Blood test — This is a more accurate pregnancy test which will measure the exact amount of hCG in the blood. Even very small amount of hCG also can be detected.
Radiography is an indispensible diagnostic tool of modern medicine that uses X-rays for imaging of internal body parts such as bones, tissues, organs, and vessels. Various radiography methods include -
X-rays — Offers a low cost first-look exam, used in detecting bone injuries.
Mammography — used in the treatment of breast cancer, to detect tumors of the breasts.
Computer Tomography(CT) — It produces 360 degree cross sectional views, used in the treatments of nearly all parts of the body such as brain, chest, heart, lungs, and abdomen.
8. Magnetic resonance imaging (MRI):
This technology uses a powerful magnetic field with an advanced computer system and radio waves to produce accurate and detailed picture of organs, soft tissues, bones, and other internal body structures. MRI provides more clear views of the tissues than a CT scan image which helps to understand differences between normal and abnormal tissues. Another advantage of MRI is that it is absolutely harmless because unlike CT scan there is no radiation involved in this process.
9. Ultrasound / Ultrasonic Imaging:
Ultrasound scanning or ultrasonography uses ultrasonic waves ( very high frequency sound waves) to produce images of internal body parts such as organs, tissues, and vessels. Ultrasound scanning has major applications in prenatal scanning (echographs) or scanning of the fetus to detect and treat if there is any disorder.
Ultrasound is an absolutely harmless method as there is no radiation involved in it and is also quicker, easier, and less costly than CT scan or MRI.
10. RSV Swab:
RSV is a seasonal virus called respiratory syncytial virus usually infects young children and older adults. RSV testing detects RSV in nasal secretions. Outbreaks typically starts during November or December and continues till the arrival of spring. If not treated RSV can cause pneumonia and bronchiolitis.
The NP (nasopharyngeal) swab is collected by inserting a swab into the suspected person’s nostril, about 1–2 inches in, and then rotating it gently a few times before withdrawing.