Your body.
Biology, side effects, recovery and everyday life between donations.
36 guides
A positive diet: the evidence-based answer
The "A types should be vegetarian" rule is diet-book lore. No controlled study supports type-based eating.
AB negative diet and the AB blood type
AB− is the rarest of the eight groups, and the type-diet books have no special science for it either.
Alcohol, smoking and blood donation, the honest rules
No alcohol for 24 hours before donating. Smoking doesn't disqualify you. Drugs: declare. The questionnaire exists to protect you and the patient.
B positive diet: what B+ people should really eat
Dairy-friendly "B diet" claims have no research behind them. Eat like a human, not like a type.
Blood disorders, explained, anaemia to thalassemia, sickle
Major blood disorders in plain language: anaemia, thalassemia, sickle cell, haemophilia, leukemia, dengue and why voluntary donors matter for each.
Blood donation and exercise, the gym, running and rest
Walk after donating; skip the heavy gym for a day. How to plan workouts around donation, and why athletes make excellent regular donors.
Blood donation during Ramadan and fasting months
Fasting Muslims can generally donate, most scholars permit it with breaking the fast if needed, and centres arrange post-iftar slots.
Blood donation side effects, the honest list
What is normal after donating (dizziness, bruising, soreness) how to care for each, and the signs that need medical attention.
Blood group and personality: does your type decide your
No. The "blood group personality" idea (popular in Japan and Korea) has been studied repeatedly and holds no scientific water.
Blood group diet plans: the honest science
The blood-group diet (eat for your A/B/O/AB) has been tested and has no scientific support. Here is what actually decides a good diet.
Blood group inheritance, how ABO and Rh actually work
Why blood groups exist, how a child's group is decided from the parents', where negative groups come from, and the rare Bombay blood group. Plain-language
Bone marrow, the factory inside your bones
How bone marrow makes billions of blood cells daily, what raw materials it needs, and why blood donation never leaves you 'running empty.'
Bruising after blood donation, what it is and what to do
Why a bruise forms at the needle site, how to care for it, how long it lasts, and the rare signs that need a doctor.
Can blood be donated after death?
No, routine blood donation ends at death. Organs and tissues can be donated, but blood from the body is not used for transfusion.
Does blood have DNA?
Yes, but mostly in your white cells. Red cells actually throw their DNA away. The strange biology, and what it means for blood tests and crime scenes.
Does donating blood help you lose weight?
No, a donation burns about 650 calories to replace the volume, but that is not a weight-loss plan and treating it as one is unsafe.
Finding blood donors on Facebook and WhatsApp: the honest
Social-media donor hunts work sometimes, here is how to do them right, and why a register beats a forwarded message every time.
Haemoglobin and anaemia, the 12.5 rule, iron, and donating
What haemoglobin does, why India's donor cutoff is 12.5 g/dL, how to read a low-Hb result, and how vegetarians keep iron up. Plain language, NBTC-aligned.
Haemoglobin: normal range and the donation cutoff
Normal Hb: roughly 12,15 g/dL for women and 13,17 for men. Donation needs at least 12.5, the finger-prick decides on the day.
How blood grouping works: how labs find your A, B, O and Rh
The two-step lab process behind every blood group, forward and reverse grouping, why errors are nearly impossible, and how to get your own group tested in
How does your body make blood? (and how fast it replaces a
Your bone marrow is a blood factory producing millions of cells per second. How blood is made, how the body replaces a donation, and why the intervals
How many litres of blood does the human body have?
The average adult has about 5 litres of blood, here's how that's calculated, why donation is safe, and where the 50 kg weight floor comes from.
Iron levels and blood donation: what every regular donor
Every donation removes about 250 mg of iron. Most bodies rebuild it from food, but regular donors, especially women, should watch their iron. Here is how.
Is blood donation safe?
Yes, for healthy adults under standard eligibility rules. What actually happens to your body, and the safeguards that protect donors.
Long-term side effects of blood donation: what years of
Regular donation over years is safe within intervals, the one real long-term watch item is iron stores in frequent donors.
O negative diet: what O− people should actually eat
No diet is specific to O negative. The high-protein "O diet" is marketing, not medicine, here is what actually matters for O− donors.
O positive diet: what actually matters for O+ people
There is no O+ specific diet. Skip the type-based eating plans; build on real fundamentals.
Plasma, the liquid that carries everything
What blood plasma is, the proteins it carries, why frozen plasma lasts up to a year, and who depends on it, from burn victims to liver patients.
Platelet count: normal range and what low means
Normal platelet counts run roughly 150,000,450,000 per microlitre. Dengue season makes this number famous, here is when it actually matters.
Platelets, the emergency repair crew
What platelets are, how clotting works, why they last only five days in storage, and why dengue season makes platelet donation vital in Assam.
Red blood cells, the oxygen couriers
What red blood cells do, why their shape and haemoglobin matter, how long they live, and why they're the heart of every blood transfusion.
What happens when you lose blood?
From a nosebleed to a serious injury, how your body responds to blood loss, when it becomes dangerous, and why a 450 ml donation is the safe end of the
What is blood? The complete biology, in plain language
What blood is made of, what each component does, how your body makes it, and why understanding this makes you a better donor. NBTC-aligned, plain language.
When to seek medical help after donating blood
The clear red-flag list after blood donation, bleeding that won't stop, spreading swelling, fever, fainting, chest symptoms, and where to go.
White blood cells, your immune army
Meet neutrophils, lymphocytes, monocytes, eosinophils and basophils, and find out why donated blood is filtered to remove most white cells.
Why is blood red? (And why do veins look blue?)
The physics and chemistry of blood colour, haemoglobin and iron, bright vs dark red, why veins look blue, and the one animal with truly blue blood.