What Blood Tests Are Done at a Routine Physical?

What are the most commonly ordered labs and what do they check?

Complete blood count (CBC). Checks red blood cells (which carry oxygen), white blood cells (which fight infection), and platelets (which help clotting). Can detect anemia, signs of infection, and certain blood cell disorders. Iron deficiency anemia, for example, is common and often first detected on a CBC before symptoms become prominent 1Ref 1Leung AKC, Lam JM, Wong AHC, Hon KL, Li X (2024).Iron Deficiency Anemia: An Updated Review.Iron deficiency anemia is common and is often detected on CBC; iron studies may be added when CBC findings or symptoms suggest deficiency.

Comprehensive or basic metabolic panel (CMP/BMP). Checks kidney function, liver function, electrolytes (sodium, potassium), and blood glucose. Gives a snapshot of organ function. Often ordered routinely, especially if you take medications that affect kidneys or liver.

Fasting lipid panel. Measures total cholesterol, LDL ('bad') cholesterol, HDL ('good') cholesterol, and triglycerides. The 2018 AHA/ACC cholesterol guideline supports using a lipid panel to assess cardiovascular risk and guide treatment decisions 2Ref 2Grundy SM, Stone NJ, Bailey AL, et al. (2019).2018 AHA/ACC/AACVPR/AAPA/ABC/ACPM/ADA/AGS/APhA/ASPC/NLA/PCNA Guideline on the Management of Blood Cholesterol.Lipid panel used to assess cardiovascular risk and guide treatment decisions per AHA/ACC guideline. This test is most accurate when drawn after fasting for 8–12 hours.

Fasting glucose or hemoglobin A1c. Screens for prediabetes and type 2 diabetes. The USPSTF recommends screening for prediabetes and type 2 diabetes in adults ages 35–70 who are overweight or obese 3Ref 3US Preventive Services Task Force (2021).Screening for Prediabetes and Type 2 Diabetes: US Preventive Services Task Force Recommendation Statement.USPSTF recommends screening for prediabetes and type 2 diabetes in adults ages 35–70 who are overweight or obese. For people already diagnosed with diabetes, A1c is used to monitor blood sugar control 4Ref 4American Diabetes Association Professional Practice Committee (2024).Standards of Care in Diabetes—2024.Hemoglobin A1c used in clinical monitoring of blood sugar control in people with diabetes.

Which tests are ordered based on age, sex, or risk?

Thyroid stimulating hormone (TSH). Checks for an underactive or overactive thyroid, which can cause fatigue, weight changes, mood shifts, and heart rhythm problems. Often checked in adults, particularly women and older adults, where thyroid conditions are more common 5Ref 5Jonklaas J, Bianco AC, Bauer AJ, et al. (2014).Guidelines for the Treatment of Hypothyroidism: Prepared by the American Thyroid Association Task Force on Thyroid Hormone Replacement.TSH testing to detect hypothyroidism, which can cause fatigue, weight changes, and other nonspecific symptoms.

HIV screening. The USPSTF recommends HIV screening for all adults ages 15–65, with more frequent testing for those at higher risk 6Ref 6US Preventive Services Task Force; Owens DK, Davidson KW, Krist AH, et al. (2019).Screening for HIV Infection: US Preventive Services Task Force Recommendation Statement.USPSTF recommends HIV screening for all adults ages 15–65 as a routine preventive recommendation. This is a routine preventive recommendation, not only for people with symptoms.

Sexually transmitted infection screenings. STI screenings (syphilis, hepatitis C, hepatitis B, chlamydia in sexually active women under 25) are recommended at certain ages or risk levels as part of preventive care.

Vitamin D. Not a routine universal test — typically ordered when there is reason to suspect deficiency based on symptoms (fatigue, bone pain) or risk factors like limited sun exposure.

Iron studies. Added if the CBC shows anemia or if there are symptoms consistent with iron deficiency 1Ref 1Leung AKC, Lam JM, Wong AHC, Hon KL, Li X (2024).Iron Deficiency Anemia: An Updated Review.Iron deficiency anemia is common and is often detected on CBC; iron studies may be added when CBC findings or symptoms suggest deficiency.

What tests are NOT typically routine at a standard physical?

Some tests that people expect at a physical are actually only ordered based on specific symptoms or risk factors:

• PSA (prostate-specific antigen) for prostate cancer screening is a shared decision between patient and clinician, not a routine automatic order.
• Hormone panels beyond thyroid (testosterone, estrogen, cortisol) are generally ordered when there is a clinical reason, not as standard screening.
• Cancer marker blood tests (CA-125, CEA) are not recommended as general screening tools for people without symptoms.

More testing is not always better — screening only produces net benefit when the right test is applied to the right population. Ask your clinician whether a specific test makes sense for your situation.

What should you do before your bloodwork?

Some tests — particularly fasting glucose and a full lipid panel — are most accurate when drawn after fasting for 8–12 hours (water is fine). Your clinician's office will usually tell you whether to fast ahead of your visit. If you are not sure, call and ask.

If you have recent lab results from another provider, bringing them can help avoid duplicate testing and give your clinician useful comparison data. Bring a list of current medications and supplements — some significantly affect lab values.