Introduction
The HAS-BLED score tells you how likely a person with atrial fibrillation (AFib) is to have a major bleed in the next year while taking blood thinners. Doctors use it along with stroke risk scores like CHA₂DS₂-VASc to plan safer care.
The name HAS-BLED stands for the things it checks: Hypertension, Abnormal kidney or liver function, Stroke history, Bleeding history, Labile INR, Elderly (over 65), and Drugs or alcohol use.1 Each item is worth 1 point. The total runs from 0 to 9.3
A score of 0 means low risk, 1 or 2 means moderate risk, and 3 or more means high risk.4 A high score does not mean a patient must stop blood thinners. It means the care team should fix the problems they can change, like high blood pressure, NSAID use, or heavy drinking, and check on the patient more often.2
Answer the nine questions below and press Calculate. You get the total score, the risk group, the estimated yearly bleeding rate from the Pisters 2010 study, a step-by-step breakdown, and a chart that shows how your score compares to others.
How to use our HAS-BLED Calculator
Answer Yes or No to nine bleeding risk questions about your patient. The calculator gives a HAS-BLED score out of 9, a risk level, and the chance of major bleeding in one year.
Hypertension: Pick Yes if blood pressure is not controlled and the top number (systolic) is over 160 mmHg.2
Abnormal renal function: Pick Yes if the patient is on dialysis, had a kidney transplant, or has creatinine over 2.26 mg/dL.4 That is about 200 µmol/L.
Abnormal liver function: Pick Yes for cirrhosis, or bilirubin more than 2 times normal with AST, ALT, or ALP more than 3 times normal.4
Stroke history: Pick Yes if the patient has had a stroke before, either ischemic or hemorrhagic.4 Pick Yes for a past TIA (mini-stroke) too.
Prior major bleeding or predisposition: Pick Yes for a past major bleed, a bleeding disorder, or anemia.2
Labile INR: Pick Yes if INR is unstable or high, or time in therapeutic range (TTR) is under 60%.2
Elderly: Pick Yes if the patient is older than 65 years.1
Drug usage: Pick Yes if the patient takes antiplatelet drugs like aspirin or clopidogrel, or NSAIDs.5
Alcohol use: Pick Yes if the patient drinks 8 or more units of alcohol a week.4
Calculate: Press Calculate to see the total score, risk group, bleeding rate, a full breakdown, and a chart. Press Reset to start over, or Load an Example to see a sample case.
What Is the HAS-BLED Score?
The HAS-BLED score estimates the chance that a person with atrial fibrillation (AFib) will have major bleeding within one year while taking a blood thinner. Doctors use it to spot bleeding risks early and fix the ones that can be fixed. Pisters and colleagues created it in 2010 using data from 3,978 patients in the Euro Heart Survey.1
What the Letters Mean
Each letter stands for one bleeding risk factor. Each risk factor that is present adds 1 point. The highest possible score is 9.3
- H for Hypertension: blood pressure not controlled, top number over 160 mmHg2
- A for Abnormal kidney function: dialysis, a kidney transplant, or creatinine over 2.26 mg/dL4
- A for Abnormal liver function: cirrhosis, or high bilirubin and liver enzymes
- S for Stroke: a past stroke or mini-stroke (TIA)
- B for Bleeding: past major bleeding, or a condition that makes bleeding easy, like anemia
- L for Labile INR: unsteady blood test results, in range less than 60% of the time (warfarin users)2
- E for Elderly: older than 65 years1
- D for Drugs: aspirin, clopidogrel, or NSAIDs like ibuprofen
- D for Drinking: 8 or more units of alcohol per week4
How to Read the Score
A higher score means a higher chance of a serious bleed.
- 0 points: Low risk. About 1.13 major bleeds per 100 patients each year.2
- 1 or 2 points: Moderate risk. About 1.02 bleeds per 100 patients each year at 1 point and 1.88 at 2 points.2
- 3 or more points: High risk. About 3.74 at 3 points, 8.70 at 4 points and 12.50 at 5 points, per 100 patients each year.2 No rate is shown for scores above 5.
A High Score Does Not Mean Stop Blood Thinners
This is the most important point. A score of 3 or higher is a warning flag, not a stop sign.3 For many people with AFib, the risk of stroke without a blood thinner outweighs the risk of a major bleed with one.6 A high score tells the care team to watch the patient more closely and to fix the risks that can change: control blood pressure, keep INR steady, stop unneeded aspirin or NSAIDs, and cut back on alcohol. Age, past stroke, and kidney or liver disease cannot be changed, but the others often can.
Who Should Use It
HAS-BLED is made for adults with atrial fibrillation who are taking or starting an anticoagulant. It is often used next to the CHA₂DS₂-VASc score, which measures stroke risk. Looking at both scores together helps doctors and patients weigh the good and the bad of blood thinners. Check the score again over time, since health and medicines change.4
Limits to Know
US heart guidelines note that bleeding scores like HAS-BLED do a poor job of telling apart patients who will bleed from those who will not.4 It gives an estimate for a group of people, not a promise for one person. It is a guide for talks with your doctor, not a substitute for medical advice.