How often should you get blood work done?

Who this guidance is for

The screening intervals on this page are for people without symptoms, not for monitoring a condition that is already diagnosed. The 2019 ACC/AHA primary prevention guideline covers adults without known cardiovascular disease. The USPSTF statin recommendation covers adults with no signs or symptoms of cardiovascular disease, and does not apply to adults with LDL above 190 mg/dL or known familial hypercholesterolaemia. The USPSTF diabetes recommendation covers nonpregnant adults with no symptoms of diabetes.

If you have a diagnosis, are pregnant or are on treatment, your doctor sets your schedule, and it takes priority over any general interval.

Quick guide by age and risk

• Ages 9 to 11 and 17 to 21: cholesterol checked at least once in each window (CDC).
• Adults 20 to 39: cardiovascular risk factors assessed at least every 4 to 6 years (ACC/AHA); most healthy adults have cholesterol checked every 4 to 6 years (CDC).
• Adults 40 to 75: a 10-year cardiovascular risk estimate, which guides decisions about statins (ACC/AHA, USPSTF).
• All adults from 35: screening for prediabetes and type 2 diabetes, repeated at least every 3 years if normal (ADA).
• Any age with overweight or obesity plus a risk factor: diabetes screening should be considered now (ADA).
• Prediabetes: tested yearly. Past gestational diabetes: tested at least every 1 to 3 years (ADA).
• Heart disease, diabetes or a family history of high cholesterol: cholesterol checked more often (CDC).

Cholesterol: how often by age and risk

The CDC says most healthy adults should have their cholesterol checked every 4 to 6 years, and that people with heart disease, diabetes or a family history of high cholesterol need it checked more often. A standard test measures LDL, HDL, triglycerides and total cholesterol.

For adults aged 20 to 39, the 2019 ACC/AHA guideline says it is reasonable to assess traditional cardiovascular risk factors at least every 4 to 6 years. From 40 to 75, clinicians should routinely assess those risk factors and calculate your 10-year risk of atherosclerotic cardiovascular disease, as the start of a conversation rather than the sole basis for medicine. The 2018 cholesterol guideline adds that screening can use fasting or non-fasting lipid measurement.

The USPSTF recommends a statin for adults aged 40 to 75 who have one or more risk factors (dyslipidaemia, diabetes, high blood pressure or smoking) and a 10-year risk of 10% or more. At 7.5% to under 10%, clinicians may offer one selectively. For adults 76 and older, the USPSTF finds the evidence insufficient to judge. Decisions about medicine belong with your doctor.

Diabetes and HbA1c: how often by age and risk

The American Diabetes Association's 2026 Standards of Care say screening should begin at age 35 for everyone. It should be considered at any age in adults with overweight or obesity and one or more risk factors, such as a first-degree relative with diabetes, high blood pressure, low HDL or high triglycerides, polycystic ovary syndrome or physical inactivity. If results are normal, repeat screening at a minimum of 3-year intervals is reasonable, sooner if symptoms appear or risk changes.

The USPSTF recommendation is narrower: it covers adults aged 35 to 70 who have overweight or obesity, using fasting plasma glucose, HbA1c or an oral glucose tolerance test. It suggests every 3 years may be reasonable when results are normal, and earlier screening for groups with higher rates of diabetes, including American Indian, Alaska Native, Black and Hispanic or Latino people, and people with a family history of diabetes, past gestational diabetes or polycystic ovary syndrome. A diagnosis of type 2 diabetes should be confirmed with repeat testing.

Under ADA criteria, an HbA1c of 5.7% to 6.4% is in the prediabetes range and 6.5% or above is in the diabetes range.

Monitoring is different from screening

Once a condition is diagnosed or treated, tests come more often. For people with diabetes, the ADA advises assessing glucose status at least twice a year, and more often, such as every 3 months, for people not meeting their goals or with recent treatment changes. For people starting a statin or changing its dose, the 2018 ACC/AHA guideline advises a repeat lipid test 4 to 12 weeks later, then every 3 to 12 months as needed.

How soon a re-test shows lifestyle change

HbA1c reflects average blood glucose over about the past 2 to 3 months, weighted towards recent levels, because red blood cells live for about 120 days (ADA). A test only a few weeks after a change still carries much of the old picture. The ADA notes that measuring about every 3 months shows whether glucose goals have been reached and maintained.

Lipids are judged on a similar timescale. The 2018 ACC/AHA guideline uses repeat lipid tests to assess the response to both medicines and lifestyle changes, measured as the percentage fall in LDL from baseline. The earlier ATP III guideline from the NHLBI gave lifestyle change 3 months before doctors considered adding medicine for people without heart disease or an equivalent risk.

Comparisons are fairest when both tests are taken the same way, with the same fasting state and, where possible, the same lab.

When to speak to a doctor

Ask your doctor to set your own schedule if you have a family history of high cholesterol or diabetes, overweight with any diabetes risk factor, past gestational diabetes or prediabetes. If a result comes back outside the range, your doctor decides when to repeat it, which can be sooner than any screening interval. Symptoms need a doctor whatever your last result said.