Pre-Surgery Blood Tests: What the Pre-Operative Panel Checks and Why It Matters

Quick answer: A typical pre-operative panel includes a CBC, blood sugar (and HbA1c if diabetic), kidney function and electrolytes, coagulation tests (PT/INR and aPTT), blood group and Rh type, viral markers (HIV, HBsAg, HCV), and a urine routine, often with an ECG and chest X-ray for older patients or those with heart or lung conditions. The exact list depends on your age, health and type of surgery — always follow the list your surgeon or anaesthetist gives you.

Whether it's a knee replacement, gallbladder removal, cataract surgery or a C-section, pre-surgery tests serve one purpose: to make sure your body can handle anaesthesia and surgery safely, and to prepare for any problems before they happen.

What Each Pre-Operative Test Checks

Complete Blood Count (CBC)

• Haemoglobin: anaemia increases surgical risk and may need correction before major surgery
• White cells: a high count may indicate an infection that should be treated first
• Platelets: low platelets increase bleeding risk

See understanding CBC.

Coagulation Profile — PT/INR and aPTT

These measure how quickly your blood clots. They are especially important if you take blood thinners, have liver disease, or have a history of easy bruising or bleeding.

Blood Sugar and HbA1c

Uncontrolled diabetes raises the risk of infection and slows wound healing. Many surgeons want HbA1c below a certain level before elective surgery. See HbA1c explained.

Kidney Function Test and Electrolytes

Creatinine, urea, sodium and potassium tell the anaesthetist how your body will handle fluids and medicines. Abnormal potassium in particular can affect heart rhythm during surgery. See kidney function tests.

Liver Function Test

Often added for major surgery, older patients or anyone with liver disease or alcohol use, because the liver processes many anaesthetic drugs. See LFT guide.

Blood Group and Rh Typing

Needed in case a blood transfusion is required. Read why everyone should know their blood group.

Viral Markers — HIV, HBsAg (Hepatitis B), Anti-HCV (Hepatitis C)

Standard in most Indian hospitals before surgery, to protect patients and staff and plan precautions. These are done with consent. See hepatitis B and C screening.

Urine Routine

Screens for urinary infection, sugar and kidney issues — an untreated UTI can be a reason to delay surgery, especially urological or joint replacement procedures.

ECG

Usually advised for patients over 40–50, and anyone with heart disease, diabetes, high blood pressure or breathlessness.

Chest X-Ray

Often advised for older patients, smokers, and those with heart or lung disease or a current cough. See our chest X-ray guide.

Additional Tests in Some Cases

• Thyroid profile — if you have thyroid disease
• Serum albumin — nutritional status before major surgery
• Pregnancy test — women of child-bearing age, before procedures where it matters
• Echocardiogram, PFT or specialist review — for heart or lung conditions, as advised

How Early Should You Get Pre-Op Tests Done?

Most hospitals accept pre-operative tests done within 2–4 weeks before surgery, though some prefer within 7 days, particularly for CBC and electrolytes. Ask your surgeon's team. Getting tests done early gives time to correct problems — like low haemoglobin or high sugar — without postponing the surgery date.

How to Prepare

• Fast for 8–12 hours if fasting sugar or lipids are included (water allowed)
• Carry your surgeon's test list and any previous reports
• Tell the lab about blood thinners (aspirin, clopidogrel, warfarin, newer anticoagulants) — don't stop them without your doctor's advice
• Bring a list of all your medicines and supplements
• For older parents, consider home sample collection to avoid an extra trip

Report Turnaround at Aarvak

• CBC, sugar, KFT, LFT, electrolytes, urine routine: typically within 6–8 hours
• Coagulation profile and blood group: same day
• Viral markers: usually same day or next day
• ECG: immediate; chest X-ray: same-day radiologist report

Frequently Asked Questions

What blood tests are done before surgery?

Common pre-operative tests include CBC, blood sugar, kidney function and electrolytes, PT/INR and aPTT, blood group and Rh, HIV, HBsAg and HCV, and urine routine. ECG and chest X-ray are added based on age and health.

How many days before surgery should tests be done?

Usually within two to four weeks before surgery, though some hospitals require certain tests within seven days. Check with your surgeon's team.

Why is a PT/INR test done before surgery?

PT/INR checks how quickly your blood clots. It helps identify bleeding risk, especially in people on blood thinners or with liver disease.

Is fasting required for pre-operative blood tests?

Fasting is needed only if fasting blood sugar or a lipid profile is included. Other pre-op tests do not need fasting.

Can I get pre-surgery tests done outside the hospital?

Many hospitals accept reports from a qualified diagnostic lab. Check with your hospital first and take the test list they provide.

Can pre-op tests be done at home in Gurugram?

Blood and urine tests can be collected at home. ECG and chest X-ray need a visit to our Sector 67 centre.

Book Your Pre-Operative Tests in Gurugram

Call +91 92663 33711 with your surgeon's test list — we'll confirm what's needed, the cost and turnaround in advance. Contact us to book.

This article is for general information only. Always follow the pre-operative instructions given by your surgeon and anaesthetist.