The 10 Most Important Lab Tests Everyone Should Know

If you haven’t been to a doctor or gotten bloodwork done in a few years, get these 10 lab tests today.

Feeling off and don’t know why? Gaining weight, or struggling to lose it? Feeling low energy? Or just want to avoid the risk of disease? Then you should know these 10 tests and get them every year.

Your body can be dealing with serious health issues long before you feel anything is wrong, making lab tests one of the most powerful early-detection tools available. These 10 tests are the best way to know if there’s something wrong with your body, before it becomes a real issue. 

What These Tests Help You Uncover

Together, these labs can flag early signs of 500+ health conditions. They reveal issues across multiple systems in your body:

• Metabolism – how your body processes energy, stores fat, and regulates blood sugar
• Inflammation – the underlying cause of many chronic diseases
• Thyroid and hormone function – regulators of energy, mood, and weight
• Liver and kidney health – your body's filtration and detoxification systems
• Nutrient status – deficiencies affecting bone health, immunity, and brain function
• Cardiovascular risk – early warning signs before heart disease develops

Because biochemical markers change early, these tests give you a high-level snapshot of your health, so you can know what's happening beneath the surface before it becomes a problem.

The 10 Most Important Lab Tests Everyone Should Know

1. Complete Blood Count (CBC)

What it measures: Red blood cells, white blood cells, hemoglobin, hematocrit, platelets

Why it matters: Your blood is a transport and defense system. Red cells carry oxygen to every tissue, white cells fight infection, and platelets prevent bleeding. If a CBC test shows abnormal numbers, it signals that something is affecting your body's core functions.

Detects: Anemia, infections, immune issues, inflammation, blood disorders, bone marrow problems.

Normal ranges:

• WBC: 4.0–11.0 × 10⁹/L
• Hemoglobin: 13.5–17.5 g/dL (men), 12.0–15.5 g/dL (women)
• Platelets: 150–400 × 10⁹/L

Sample Type: Blood | Fasting Required: No

2. Comprehensive Metabolic Panel (CMP)

What it measures: Liver enzymes, kidney markers, glucose, electrolytes, calcium, protein

Why it matters: This panel evaluates how well your liver, kidneys, and metabolic systems are functioning. Your liver processes toxins, your kidneys filter waste, and your electrolytes keep your heart beating in rhythm. When any of these drift out of range, it's an early sign of metabolic dysfunction.

Detects: Kidney disease, liver damage, diabetes, electrolyte imbalances, dehydration, metabolic syndrome

Sample Type: Blood | Fasting Required: Yes (8–12 hours)

3. Lipid Panel

What it measures: LDL, HDL, triglycerides, total cholesterol

Why it matters: Cholesterol is essential for hormones and cell membranes, but when LDL accumulates in artery walls or triglycerides stay elevated, cardiovascular risk increases. This panel shows whether your lipid balance is protective or problematic.

Detects: High cholesterol, cardiovascular disease risk, metabolic syndrome, atherosclerosis

Normal ranges:

• Total cholesterol: <200 mg/dL
• LDL: <100 mg/dL
• HDL: >40 mg/dL (men), >50 mg/dL (women)
• Triglycerides: <150 mg/dL

Sample Type: Blood | Fasting Required: Yes (9–12 hours)

4. Hemoglobin A1c

What it measures: Average blood sugar over the past 3 months

Why it matters: Unlike a single glucose reading that captures a single moment’s blood sugar levels, A1c reveals your long-term blood sugar control. It's a window into how well your body manages glucose and whether insulin resistance or diabetes is developing without you realizing.

Detects: Prediabetes, type 2 diabetes, blood sugar control issues

Normal ranges:

• Normal: <5.7%
• Prediabetes: 5.7–6.4%
• Diabetes: ≥6.5%

Sample Type: Blood | Fasting Required: No

5. Thyroid Panel (TSH, Free T4, Free T3)

What it measures: TSH (brain signal), Free T4 (inactive hormone), Free T3 (active hormone)

Why it matters: Your thyroid controls metabolism, energy production, body temperature, and mood. When it's underactive, everything slows down, leading to fatigue, weight gain, and brain fog. When it's overactive, everything speeds up, causing anxiety, weight loss, rapid heartbeat. A thyroid panel reveals the full picture.

Detects: Hypothyroidism, hyperthyroidism, Hashimoto's, Graves' disease, poor hormone conversion

Normal ranges:

• TSH: 0.4–4.0 mIU/L
• Free T4: 0.8–1.8 ng/dL
• Free T3: 2.3–4.2 pg/mL

Sample Type: Blood | Fasting Required: No

6. Vitamin D (25-Hydroxy)

What it measures: Storage form of vitamin D

Why it matters: Vitamin D regulates immune function, mood, inflammation, and bone health. Low levels are linked to depression, autoimmune disease, poor immunity, and increased fracture risk. A Vitamin D 25-Hydroxy test will show if your levels are low.

Detects: Vitamin D deficiency, seasonal depression, osteoporosis risk, immune dysfunction

Normal ranges:

• Deficient: <20 ng/mL
• Insufficient: 20–30 ng/mL
• Optimal: 30–50 ng/mL

Sample Type: Blood | Fasting Required: No

7. Basic Metabolic Panel (BMP)

What it measures: Glucose, calcium, electrolytes (sodium, potassium, chloride, bicarbonate), kidney markers

Why it matters: This streamlined panel focuses on kidney function, blood sugar, and electrolyte balance. It's ideal for monitoring hydration status, kidney strain from medications, or metabolic shifts during illness or intense training.

Detects: Kidney disease, dehydration, electrolyte imbalances, diabetes, acid-base disorders

Sample Type: Blood | Fasting Required: Recommended (8–12 hours)

8. High-Sensitivity C-Reactive Protein (hs-CRP)

What it measures: Low-grade systemic inflammation

Why it matters: CRP is produced by the liver in response to inflammation. Unlike regular CRP tests that detect acute infections, hs-CRP picks up chronic inflammation that damages arteries, promotes insulin resistance, and accelerates aging. It's one of the best predictors of future cardiovascular events.

Detects: Cardiovascular inflammation, chronic disease risk, autoimmune activity, obesity-related inflammation

Normal ranges:

• Low risk: <1.0 mg/L
• Moderate risk: 1.0–3.0 mg/L
• High risk: >3.0 mg/L

Sample Type: Blood | Fasting Required: No

9. Liver Function Tests (LFTs)

What it measures: ALT, AST, ALP, bilirubin, albumin, total protein

Why it matters: Your liver processes medications, alcohol, dietary fats, hormones, and toxins. When liver cells are stressed or damaged, enzymes leak into the bloodstream. This panel reveals whether your liver is inflamed, overworked, or struggling to detox your body. 

Detects: Fatty liver disease, hepatitis, cirrhosis, alcohol-related damage, bile duct obstruction, medication toxicity

Sample Type: Blood | Fasting Required: Sometimes

10. Kidney Function Panel

What it measures: Creatinine, BUN, eGFR (estimated filtration rate)

Why it matters: Your kidneys filter about 50 gallons of blood every day. When filtration declines, waste builds up in the bloodstream, leading to fatigue, swelling, high blood pressure, and eventually kidney failure. This panel detects decline early, often years before symptoms appear.

Detects: Chronic kidney disease, acute kidney injury, dehydration, medication-related damage, diabetic nephropathy

Normal ranges:

• Creatinine: 0.7–1.3 mg/dL (men), 0.6–1.1 mg/dL (women)
• BUN: 7–20 mg/dL
• eGFR: >60 mL/min/1.73m²

Sample Type: Blood | Fasting Required: No

Bonus: TheLabCafe Functional Health Assessment Panel

What it includes: CMP, CBC, thyroid panel (TSH, Free T4, Free T3), A1c, Lipid Panel, Vitamin D, Lipoprotein(a), urinalysis

Why it matters: The Functional Health Assessment Panel combines all the most useful tests into one assessment. Evaluates metabolism, thyroid, cardiovascular risk, inflammation, kidney health, blood quality, and nutrient status all at once.

Sample Type: Blood + urine | Fasting Required: Yes (8–12 hours)

High-Value Tests for Maximum Clarity

Blood markers shift early, long before symptoms appear. These tests give you clear, actionable insights for prevention and understanding your body. Direct-to-lab testing makes them fast, affordable, and accessible.