Why it matters:
Symptoms of low HB:
Why it matters:
🩸 1. Platelets (Thrombocytes)
Platelets are small blood components that help in clotting.
🧪 2. Eosinophils
Eosinophils are a type of white blood cell (WBC) involved in immune response.
Seen in:
PT (Prothrombin Time) measures how many seconds it takes for blood to clot through the extrinsic pathway of coagulation.
It reflects the function of clotting factors made in the liver.
📊 What is INR?
INR (International Normalized Ratio) is a standardized version of PT so results are consistent worldwide.
⚙️ Why PT/INR is Important
⚠️ High PT/INR (Blood clots slowly)
Causes:
Risk: Bleeding
⚠️ Low PT/INR (Blood clots quickly)
Causes:
Risk: Thrombosis (clots forming in vessels)
🩸 What does aPTT measure?
It evaluates several clotting factors (like VIII, IX, XI, XII) and helps detect problems in the clotting system.
📌 Normal Range
⚙️ Why is the aPTT test done?
⚠️ High aPTT (Prolonged clotting time)
Means blood is taking longer to clot.
⚠️ Low aPTT (Short clotting time)
Less common, may indicate:
🔬 PT vs aPTT (Quick Difference)
TestPathway CheckedCommon UsePT / INRExtrinsic pathwayMonitor WarfarinaPTTIntrinsic pathwayMonitor heparin therapy
🧾 Simple Summary
BLOOD TYPE (ABO-RH)
🩸 ABO Blood Group System
The ABO system classifies blood based on antigens present on red blood cells.
Reticulocyte count is a blood test that measures the number of reticulocytes—immature red blood cells (RBCs)—in your blood. It shows how actively your bone marrow is producing new RBCs.
Means bone marrow is working harder to replace lost RBCs.
Seen in conditions like:
Means decreased RBC production.
Seen in:
In anemia, doctors often calculate a corrected reticulocyte count to get a more accurate picture of marrow activity.
Reticulocyte CountMeaningHighRBC loss or destructionLowPoor RBC production
🩸 What is CBC?
A Complete Blood Count (CBC) measures:
🔴 1. Red Blood Cells (RBC)
Carry oxygen from lungs to tissues
🧪 2. Hemoglobin (Hb)
Protein in RBC that carries oxygen
⚪ 3. White Blood Cells (WBC)
Fight infection and protect body
Related condition:
🩸 4. Platelets
Help blood clotting
🧬 5. RBC Indices
These give extra details about red cells:
Used to classify types of anemia.
🧫 6. Differential Count (DLC)
Shows types of WBCs:
🧪 What is the Mantoux Test?
It is a skin test where a small amount of a protein called tuberculin (PPD – purified protein derivative) is injected just under the skin of the forearm.
🩺 Purpose
The test helps to detect:
It does not confirm active TB disease by itself.
⚙️ How it is done
📏 Interpretation (very important)
Only the hard swelling (not redness) is measured.
Risk factors include:
⚠️ False results
💉 Advantages
❗ Limitations
🔬 Related disease
🧪 What is the Widal Test?
It detects antibodies in the blood that the body produces against Salmonella bacteria.
These antibodies are:
🦠 Purpose
The test is used to support the diagnosis of:
These infections are usually spread through contaminated food or water.
⚙️ How it is done
📊 Interpretation
A rising antibody titer is more important than a single test result.
Common guide:
👉 A single Widal test is not always reliable, especially in early infection.
⚠️ Limitations of Widal Test
The Widal test has several drawbacks:
🧫 Better alternatives today
Modern and more reliable tests include:
🩺 Symptoms of typhoid fever
🧪 What is the VDRL test?
The VDRL test detects non-specific antibodies (reagin antibodies) produced by the body when infected with syphilis-causing bacteria.
The bacteria responsible is:
🦠 Purpose
The test is used to:
⚙️ How it is done
📊 Interpretation
🔍 Important point
👉 VDRL is a screening test, not a confirmatory test.
If VDRL is positive, it is usually confirmed with:
⚠️ False results
🩺 Uses of VDRL test
💡 Key takeaway
🧪 What is an aldehyde?
An aldehyde has the general structure:
R–CHO
Where:
The key feature is a carbonyl group (C=O) where the carbon is bonded to at least one hydrogen atom.
🔬 Structure (simple idea)
Example:
⚙️ Properties of aldehydes
🧫 Chemical behavior
Aldehydes:
🏭 Uses of aldehydes
🧠 Examples
HBeAg and HBsAg (Hepatitis B Envelope Antigen) are related closely to Hepatitis B levels and are hence used frequently for assessment of any activity for liver diseases. The test also detects responses to the antiviral therapies for patients suffering with infections of chronic HBV. It is also known as Australia antigen.
The HBsAg test is included in Hepatitis B Panel Blood Tests and also used in conjunction with other tests for detailed diagnosis. Hepatitis B core antigen test and Hepatitis B surface antibody tests are the other tests included in the panel of blood tests for diagnosing Hepatitis B.
Q: What is HBsAg?
A: HbsAg is the abbreviated form of Hepatitis B surface antigen.
Q: What is the other nomenclature for HBsAg ?
A: HBsAg is also known as Australia antigen.
Q: What does positive HBsAg result indicate?
A: Positive test results indicate acute or chronic infection from hepatitis B virus.
Q: How long does it take for HBsAg to be detected via blood test?
A: HBsAg levels are detectable via blood tests between 2-4 months after contracting infection.
Q: For how long after patient is treated does Hepatitis B surface antigen circulate in the blood?
A: Ideally surface antigen disappears in 2 months after patient starts manifesting symptoms. If chronic infection develops, patient may test positive for the antigen for life.
RA Factor test is a diagnostic test that helps in determining whether a person is prone to developing rheumatoid joint disorders. It is a blood test performed in pathology labs equipped with modern medical tools and technology.
Rheumatoid arthritis is an autoimmune disorder. This means that it develops due to some abnormality in the patient's immune system. Antibodies are synthesized against the patient's own body tissues, leading to the development of joint disorders. RA factor is a specific protein which attacks the cartilage of various joints and causes symptoms of discomfort.
Q: What is rheumatoid factor?
A: Rheumatoid factor is a special group of antibodies (immunoglobulin M) created against IgG (immunoglobulin G) in the body. It is most commonly seen in patients affected with rheumatoid arthritis but can also be found in other autoimmune conditions as well.
Q: How is a rheumatoid factor test done?
A: A sample of blood is collected from a vein in the arm and sent to the laboratory to be studied using advanced techniques.
Q: Why is rheumatoid factor test required?
A: An RF test may be suggested by the doctor if he/she suspects signs & symptoms of rheumatic arthritis like joint stiffness, cartilage loss, nodule formation in the skin and warmth in the joint region.
Q: Is rheumatoid factor seen only in arthritis?
A: No. Apart from rheumatoid arthritis, rheumatoid factor is also seen in conditions like polymyositis, systemic lupus erythematosus, syphilis, viral hepatitis, and influenza in some cases.
Q: What other tests are needed to diagnose rheumatoid arthritis?
A: In addition to RA factor, tests like ESR (Erythrocyte Sedimentation Rate), ANA (Anti-Nuclear Antibody) assay, CBC, CRP (C-Reactive Protein) and Anti-RA33 antibody assay can be done to diagnose rheumatoid arthritis.
The ASO test is done to determine whether the recent strep infection is group A streptococcus. Health practitioners may sometime suspect illness symptoms in patients as causes of some prior infections. This may prompt them to prescribe the ASO test. This is usually prescribed when such symptoms are detected. These are usually visible after passage of some weeks post some skin infection or sore throat issues when bacteria are abstaining on skin or inside the throat.
Q: What is ASO test?
A: Also known as antistreptolysin O titer, it is a blood test used to measure the amount of antibodies produced by the body against a specific bacteria. This bacteria is called group A Streptococcus (GAS) which produces streptolysin O.
Q: Why is the test ordered?
A: To check antibody levels against post-streptococcal complications like bacterial endocarditis, glomerulonephritis, rheumatic fever, scarlet fever, and strep throat.
Q: What causes post-streptococcal complications?
A: They are mostly caused due to symptomatic infections developed by GAS.
Q: What is the normal value of this test?
A: Below 200. In case of children, it should be less than 100.
Q: What other important information should I know?
A: If the ASO antibodies decline, your Streptococcus infection is getting reduced. Increasing level of the antibodies suggest that your infection is recent. You may want to repeat the test after 10-14 days.
The HIV test helps in determining whether the concerned person is infected with Human Immunodeficiency Virus (HIV). This virus weakens immune system of infected people and leads to AIDS. Some forms of this test check antibodies produced by the immune system while others find evidence of the presence of this virus.
Q: Which tissue sample is required for HIV test?
A: A blood sample from the patient is the most preferred tissue for performing HIV test.
Q: What are the different types of HIV tests?
A: Tests for diagnosing HIV infection include antibody detection, RNA detection, and a combination of both.
Q: What is 'window period' for HIV infection?
A: The time span between contacting infection to detection of infection through blood test is known as window period. It is anywhere between 10 days to 3 months for HIV infection.
Q: How does HIV infection spread?
A: Infected needles, unprotected sexual contact, intimate contact with body fluid of an infected person, are the commonest ways for HIV infection to spread.
Q: Can HIV test give positive result in absence of symptoms?
A: Yes, it is possible to have a positive HIV test in complete absence of any symptoms.
CRP is a test carried out to detect the C reactive protein concentration in blood. High levels of CRP indicates inflammation or long term infections in the body. The test is alternatively called ultra-sensitive-C-reactive protein (us-CRP) and high-sensitivity C-reactive protein (hs-CRP).
The levels of CRP can also rise if the arteries in your heart are inflamed. Patients with such health conditions have higher chances of a heart attack. But, the test reports do not provide a clear result in case of cardiac health. Your doctor may therefore, use more than one diagnostic test to confirm issues with arteries.
Q: What is CRP?
A: Also named as high sensitivity protein, C-reactive protein or CRP is produced as a response to inflammation by the liver.
Q: Why is CRP test ordered?
A: To examine and monitor infections and infectious diseases like rheumatoid arthritis, lymphoma, osteomyelitis, lupus, inflammatory bowel disease, giant cell arteritis, etc., check for infections post surgery, assess the risk of stroke or heart attack, and keep track of the progress of treatment for infections.
Q: What is the normal figure for CRP test?
A: <1.0 mg/dL.
Q: Does CRP test help to identify the cause and location of inflammation?
A: No.
Q: What does high CRP reading mean?
A: Pneumonia, arthritis flare-up, tuberculosis, cancer, bowel disorder, immune disease, or infection.
Allergy test helps in detecting the specific agent or agents to which a person is allergic. The test is a simple and non invasive procedure and can be done on outpatient basis. It is a blood test or a skin test.
Q: What is allergy?
A: An allergy or hypersensitivity is an abnormal immune response of the body against seemingly harmless substance. It often manifests in the form of sneezing, fever, hives and difficult in breathing.
Q: What is an allergy test?
A: Allergy tests involve studying the body's reaction to allergy causing substances (allergens). This can be done by observing skin reactions, formation of antibodies in blood or eliminating certain foods from diet.
Q: Why is allergy test required?
A: An allergy test may be needed to rule out the cause of certain conditions like hay fever, rhinitis, urticaria and asthma. Harmless substances like pollen grains or food items can trigger a life threatening response from the body. Finding out the cause helps in avoiding it altogether.
Q: How is allergy testing done?
A: You may have to undergo a routine blood test where a blood sample is drawn from your veins. Or if a skin test is done, tiny doses of allergens are applied or injected inside your skin to check for any reaction.
Q: Are there risks associated with allergy testing?
A: Though the allergens used in an allergy test are of minute quantity, chances do exist of an impending hypersensitive reaction. You may feel itchy, have a runny nose or experience anaphylaxis (a severe allergic reaction) which is a medical emergency.
HCV Antibody test is a blood test checking for the presence of antibodies against Hepatitis C virus. This test can be performed at any pathology lab which is equipped with advanced technology and instruments of high calibration. A venous blood sample collected from the patient is required to check for presence of HCV antibodies.
HCV infection has an ability to remain silent and therefore, undetected for years together. Only when the liver has sustained considerable damage, does the infection become evident due to development of symptoms.
Q: What are the indications of HCV Antibody test?
A: Yellow discoloration of skin and urine, bleeding tendency, fatigue, digestive disturbances, fever and headache, are characteristic indications of HCV Antibody test.
Q: How long after infection of Hepatitis C virus, do antibodies appear in blood circulation?
A: Hepatitis C antibodies appear in blood circulation about 6 months after contracting infection.
Q: Which tissue sample is preferred for performing HCV Antibody test?
A: Venous blood is the only tissue sample used for performing HCV antibody test.
Q: How does one contract Hepatitis C infection?
A: HCV infection is contracted if one comes in intimate contact with blood of an infected person.
Q: How can Hepatitis C infection be treated?
A: Anti-viral medicines, fever medicines, strict dietary restrictions, blood transfusion (rarely)and liver transplant (very rarely) are the various treatment options used during Hepatitis C infection.
Adenosine Deaminase
Adenosine Deaminase is a type of protein present in various cells of body. This protein is related to lymphocyte activation and is clinically tested to determine pleural tuberculosis. Pleurae are covering membranes of chest cavity and are also present at the exterior lining of lungs. When Mycobacterium Tuberculosis attacks, it causes increased production of ADA that can be detected in Pleural Fluid. Thus, Adenosine Deaminase Test is ordered, along with many other lab examinations.
Inflammation or infection of pleural cavity results in accumulation of fluid in the area, leading to various health hazards. Doctors order Adenosine Deaminase test, when patients complain of severe cough accompanied with blood, chest pain, chills and night sweats, very high fever etc. When pleural fluid shows traces of ADA, tuberculosis is confirmed.
Q: Chemically, what is ADA (Adenosine Deaminase) comprised of?
A: Adenosine Deaminase (ADA) is chemically an enzyme. It is composed of chains of complex proteins known as peptides.
Q: What are the functions of ADA?
A: In human beings, ADA is responsible for maintaining a healthy and responsive immune system and nervous system. It is also known to play a significant role during pregnancy.
Q: Which health disorders can be detected by performing ADA test?
A: ADA test is advised to determine presence and intensity of tuberculosis. Other disorders which may be diagnosed with this test are, rheumatic affections, sarcoidosis, psoriasis and other auto-immune diseases.
Q: How is ADA test performed?
A: ADA test is usually performed by obtaining pleural fluid through a process known as thoracentesis. In cases where disorders other than T.B. are to be diagnosed, a blood sample is useful to perform the test.
Q: Is ADA test useful during follow ups?
A: Yes, ADA can also be performed during follow ups. This allows doctors to assess the level of improvement in patients after medical treatment has been initiated for their specific health condition.
Antibodies are produced by the body in response to attacks by foreign agents and disease-causing germs. They are fielded by immune system for protecting the body against diseases. IgG are antibodies that appear after 14 days of visible symptoms of Dengue. Usually, dengue IgG test is done along with IgM for finding the presence of both these antibodies in human blood for further treatment.
Dengue fever is transmitted by a virus that is carried by a mosquito. The fever lasts typically from around 1-2 weeks. As mentioned before, Dengue IgG is done in conjunction with Dengue IgM.
Q: What is dengue IgG?
A: It is an antibody type produced by the body against dengue infection.
Q: What is the reference range for dengue IgG test?
A: <1.64 IV.
Q: Is there any vaccine for dengue?
A: No. The vaccine is still being researched and expected to come out soon.
Q: What time of the day is the dengue mosquito most active? When does it bite?
A: It is mostly active during morning and evening. It only bites in the day time and is not very much active at night.
Q: Do dengue symptoms resemble to those of malaria?
A: Yes, but in the initial stages.
Prostate-specific antigen
Prostate Specific Antigen (PSA) test is a blood test useful in
screening and diagnosis of prostate cancer or other prostate related disorders.
PSA is a chemical made by the prostate gland and is produced by both cancerous
and non-cancerous prostate tissues. This test estimates the amount of PSA
present in the blood. PSA monitors
response to total prostatectomy for cancer, radiation therapy.
PSA test necessitates a blood sample and results are often
obtained within a few days. Depending upon the levels of PSA, further tests and
investigations are suggested. PSA test can help detect prostate cancer in early
stages, monitor the treatment, and help plan a new course of action.
Q: BPH (Benign Prostrate Hypertrophy) is common in which age group?
A: 50 years and under.
Q: What are the distinctive characteristics of high level of PSA?
A: It is most commonly raised in BPH and prostrate cancer. Less than one third of patients with high PSA are diagnosed to suffer from due to cancer.
Q: How do you know that you have BPH?
A: Increased frequency of urination, increased tendency to urinate, and urinating at night.
Q: How regularly should prostrate cancer patients get themselves checked?
A: Regular follow up with the treatment of prostrate cancer at least at an interval of six months.
Blood Sugar test is useful to measure levels of glucose present in blood at any given time. A venous blood sample is required to perform this test. This simple blood test is conducted at most pathology labs equipped with advanced medical techniques and equipment.
Test results vary depending on the time that has passed between food intake by the patient and performing the test. This test has multiple uses and may be performed as part of routine health check up as well.
Q: What is urine sugar?
A: It is a substance found in the urine of diabetic patients or people with leaky kidneys or urine tract infection. A urine sugar/glucose test could be ordered in this case.
Q: What is home blood sugar test?
A: It is similar to routine blood sugar test which can be performed anywhere or at your home using an equipment. It helps to measure blood sugar level, evaluate and schedule insulin dose, know how body responds to stress, diet, exercise, and illnesses, and detect sugar related diseases.
Q: What causes low blood sugar?
A: Hypoglycemia, anorexia, Addison's disease, cirrhosis, hypothyroidism, diabetes, kidney malfunction, and pituitary gland tumor.
Q: What causes high blood sugar?
A: Type 2 diabetes, Cushing's syndrome, intense stress, acromegaly, stroke, heart attack, and certain medicines like corticosteroids.
Q: What is the main source of energy for brain cells?
A: Glucose which is a type of sugar in the human body.
Glucose Tolerance Test finds the body's response to sugar. This test is used as a screening tool for Type-2 diabetes as well. The Glucose Tolerance Test should be reserved principally for patients with “borderline” fasting plasma glucose levels. The test is necessary for diagnosis of impaired fasting glucose and impaired glucose tolerance. This test is also known as Oral Glucose Tolerance Test (OGTT).
Q: What is glucose tolerance test?
A: Glucose tolerance test (GTT) is a method to determine the presence of diabetes. This test has great value in diagnosing gestational diabetes.
Q: Why is glucose tolerance test needed?
A: Apart from diabetes, a GTT helps in diagnosing impaired function of beta cells (in pancreas), reactive hypoglycemia & acromegaly, insulin resistance or diseases affecting metabolism of carbohydrates.
Q: Is there any special preparation required before a Glucose Tolerance Test?
A: Yes. In the few days before testing you will be asked to have a good carbohydrate diet. Fasting is required for 8-12 hours before the test. Preferably you should not be ill and avoid medications like oral contraceptives, salicylates, diuretics and anti-convulsants for some time (only after getting the approval of your doctor).
Q: How is GTT performed?
A: Some blood is withdrawn from the vein and marked as baseline sample. A certain amount of glucose is given in solution form to drink, 2 hours after which another blood sample is taken. If renal glycosuria is suspected, urine samples may also be taken at same time intervals.
Q: What do the results of a GTT indicate?
A: A GT test shows the levels of glucose and the person's ability to metabolize it. The results of GTT in different conditions are indicated below:
In absence of diabetes
2 Hour glucose – more than 153 mg/dL
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Triglycerides test is a diagnostic test that helps to determine
the levels of fat in a person's blood. This test can be performed as part of lipidprofile test or even individually.
A venous blood sample is obtained from the patient to check for levels of triglycerides. Blood sample needs to be stored away from heat, light and moisture, till the test is completed. Highly calibrated medical instruments are used to determine levels of triglycerides, so as to obtain accurate test results.
Q: Which tissue sample is required for triglycerides tests?
A: Blood samples for triglycerides testing are drawn from veins in the forearm.
Q: Which other tests can be ordered along with triglycerides test?
A: Lipid profile, cholesterol testing and angiography can be ordered in conjunction with a triglyceride test.
Q: What are the ideal ranges of triglycerides in the body?
A: Normal levels: Less than 150 mg/dl
Borderline elevated:150 to 199 mg/dl
Elevated: 200 to 499 mg/dl
Abnormally high: 500 mg/dl or more
Q: Who is ideally required to undergo triglycerides testing?
A: People who have diabetes, high blood pressure, high cholesterol, obesity and a history of cardiac disorders, are ideal candidates for triglyceride testing.
Q: How can high triglycerides level be brought back to normal?
A: Specific lifestyle changes including adequate exercising, quitting smoking and alcohol, having a healthy diet, can help in normalizing high triglyceride levels.