Life-Saving Blood Tests That Reveal Serious Health Conditions

Blood work, also known as blood tests, is an integral part of a standard doctor's visit to check how well your organs are functioning. It can also detect any nutritional deficiencies, and anemia, and can help diagnose many chronic conditions and diseases like cancer, diabetes, and heart disease. You may not realize it, but several life-saving blood tests can reveal serious health conditions.

Blood tests assess how well organs function and reveal abnormalities that typically warrant further specific testing. As Dr. Keith Hoots of the National Heart, Lung, and Blood Institute explained, the first question after a blood test is "Is it accurate?"

Blood tests broadly screen for potential conditions that subsequent testing must confirm. They are part of a process going from general to more specific, Dr. Hoots added.

To identify life-saving blood tests that reveal serious health conditions, 24/7 Tempo conducted a review of various medical publications such as the Mayo Clinic, the U.S. National Library of Medicine, and the U.S. Food and Drug Administration press announcements.

We chose conditions where blood tests either confirm the disorder or raise red flags prompting confirmation. Information on symptoms, confirming tests, and treatment came from Mayo Clinic and other sources. (See why the women and men in these countries live the longest.)

This post was updated on October 26, 2025 to clarify confirmation tests (for PE, pregnancy, Lyme disease, HIV) and treatment (for pulmonary embolism, Gonorrhea, flu, HIV).

Here are life-saving blood tests that reveal serious health conditions:

• Common symptoms: Sneezing, watery eyes, hives, rash
• Confirmation tests: Allergy testing
• Treatment: Medication, immunotherapy

• Common symptoms: Joint stiffness, fever, fatigue
• Confirmation tests: Test for antibodies, imaging tests, additional blood tests
• Treatment: Biologic agents, disease-modifying antirheumatic drugs, steroids

• Common symptoms: Rash, swollen lymph glands, fever, weight loss
• Confirmation tests: 4th-gen antigen/antibody tests, ELISA test, saliva tests
• Treatment: Protease inhibitors (PIs), non-nucleoside reverse transcriptase inhibitors, integrase-inhibitor–based ART

• Common symptoms: Shortness of breath, chest pain, cough
• Confirmation tests: CT pulmonary angiography or V/Q scanning
• Treatment: Medications to dissolve the blood clot (Thrombolytics) andprevent further clots (blood thinners)

• Common symptoms: Slow-healing sores, extreme hunger, thirst
• Confirmation tests: Glycated hemoglobin (A1C) test, blood sugar test
• Treatment: Insulin, monitoring blood sugar

• Common symptoms: Rash
• Confirmation tests: Two-tier serologic testing (EIA/ELISA followed by immunoblot or a second EIA)
• Treatment: Antibiotics

• Common symptoms: Mild fever, rash, joint pain
• Confirmation tests: Blood or urine test
• Treatment: No antiviral treatment. No vaccine

• Common symptoms: Excessive bleeding, dark stool
• Confirmation tests: Coagulation test, or PT test
• Treatment: Phytonadione supplement

• Common symptoms: Rapid heartbeat, sweating, increased appetite, sleeping problems
• Confirmation tests: Physical exam, radioiodine uptake test, thyroid scan or ultrasound
• Treatment: Radioactive iodine, beta-blockers, surgery

• Common symptoms: Lymph swelling, fatigue, fever
• Confirmation tests: Removing lymph for testing (biopsy), physical exam
• Treatment: Chemotherapy, radiation therapy, bone marrow transplant

• Common symptoms: Pain in leg, discolored skin, feeling of warmth
• Confirmation tests: Ultrasounds, further blood tests, venography
• Treatment: Blood thinners, clot busters, filters, compression stockings

• Common symptoms: Fatigue, sudden nausea, loss of appetite, dark urine
• Confirmation tests: Blood sample
• Treatment: No specific treatment; rest, nausea management

• Common symptoms: Coughing up blood, chest pain, bone pain, headache
• Confirmation tests: CT scan, tissue sample, imaging tests
• Treatment: Surgery, radiation therapy, chemotherapy

• Common symptoms: Painful urination, pain or swelling, discharge
• Confirmation tests: Urine test, swab of affected area
• Treatment: Ceftriaxone 500 mg IM single dose (monotherapy)

• Common symptoms: Thirst, sunken eyes, listlessness
• Confirmation tests: Additional blood tests, urinalysis
• Treatment: Electrolytes, intravenous fluids

• Common symptoms: Flaky skin on nipple, redness, lumps
• Confirmation tests: Physical exam, breast biopsy, sentinel lymph biopsy
• Treatment: Simple mastectomy, lumpectomy

• Common symptoms: Back pain, weight loss
• Confirmation tests: Bone density measurement, X-rays
• Treatment: Bisphosphonates, hormone-related therapy

• Common symptoms: Confusion, nausea, slurred speech
• Confirmation tests: Neurological examination, review of medical history
• Treatment: Brief (24–48 hours) relative rest then graded return to activity

• Common symptoms: Rectal bleeding, weight loss, weakness
• Confirmation tests: Colonoscopy, further blood tests
• Treatment: Surgery, radiation therapy, chemotherapy

• Common symptoms: Fever, headache, sore throat
• Confirmation tests: Physical exam, polymerase chain reaction testing
• Treatment: Liquids, fluids, pain medication, antivirals (oseltamivir, zanamivir, baloxavir, peramivir)

• Common symptoms: Chest pain, shortness of breath, heart attack
• Confirmation tests: Electrocardiogram (ECG), echocardiogram, stress test
• Treatment: Beta-blockers, bypass surgery, stent placement

• Common symptoms: Jaundice, abdominal pain, itchy skin, dark urine, loss of appetite
• Confirmation tests: Additional blood tests, imaging tests, tissue analysis
• Treatment: Lifestyle modification, liver transplant

• Common symptoms: Yellow skin
• Confirmation tests: Complete blood count, liver function tests
• Treatment: None, disease usually resolves itself

• Common symptoms: Bleeding and bruising, swelling, confusion
• Confirmation tests: Genotype test, viral load test, additional blood tests
• Treatment: Antiviral medications, liver transplantation

• Common symptoms: Pelvic area discomfort, weight loss, bloating
• Confirmation tests: Pelvic exam, imaging tests, additional blood tests, surgery
• Treatment: Targeted therapy drugs, chemotherapy, surgery

• Common symptoms: Weight gain, fatigue, increased sensitivity to cold or heat, muscle aches
• Confirmation tests: Pelvic exam, ultrasound
• Treatment: Hormone therapy

• Common symptoms: Nausea, vomiting, loss of appetite, sleep problems
• Confirmation tests: Urine tests, imaging tests, kidney biopsy
• Treatment: Blood pressure, anemia, cholesterol, swelling, medications

• Common symptoms: Breast lump, redness of breast skin, change of shape of breast
• Confirmation tests: Mammogram, breast ultrasound, biopsy
• Treatment: Lumpectomy, mastectomy, radiation, chemotherapy

• Common symptoms: Fatigue, itchy skin, jaundice
• Confirmation tests: Magnetic resonance elastography (MRE), biopsy
• Treatment: Treatment for alcohol dependency, liver transplant surgery

• Common symptoms: Nausea, late period, increased urination
• Confirmation tests: hCG (urine/serum)
• Treatment: Consult physician

• Common symptoms: Fever and chills, nausea, vomiting, diarrhea
• Confirmation tests: Enzyme-linked immunosorbent assay (ELISA) test
• Treatment: Fluid and blood replacement, hospital care

• Common symptoms: Gеnital rash, hair loss, muscle aches
• Confirmation tests: Further blood tests, spinal tap
• Treatment: Antibiotics (usually penicillin)

• Common symptoms: Facial rash, fever, fatigue, joint pain
• Confirmation tests: Further blood and urine tests, chest x-ray, echocardiogram
• Treatment: Nonsteroidal anti-inflammatory drugs (NSAIDs), corticosteroids, immunosuppressants

• Common symptoms: Memory loss, poor coordination, isolation, alcohol withdrawal
• Confirmation tests: Carbohydrate-deficient transferrin blood test, DSM-5 diagnosis
• Treatment: Behavioral treatments, medication, mutual-support groups

• Common symptoms: Hot flashes, night sweats, irregular periods, weight gain
• Confirmation tests: Review of symptoms, menstrual cycle tracking
• Treatment: OTC vaginal lubricants, improved diet, hormone replacement therapy

• Common symptoms: Sores and ulcers on gеnitals
• Confirmation tests: Viral culture, polymerase chain reaction, additional blood tests
• Treatment: No cure, medication for symptoms

• Common symptoms: Swollen tonsils, fatigue, fever
• Confirmation tests: Antibody tests, white blood cell count
• Treatment: No treatment available

• Common symptoms: Bone pain, weight loss, nose bleed recurrent
• Confirmation tests: CBC, smear, bone marrow biopsy, flow cytometry
• Treatment: Stem cell transplant, radiation, biological therapy

• Common symptoms: Memory loss, depression, loss of inhibitions
• Confirmation tests: Physical tests, neurological tests, further blood tests, brain imaging
• Treatment: Cholinesterase inhibitors, Memantine

• Common symptoms: Fatigue, bloated feeling, heartburn, stomach pain
• Confirmation tests: Upper endoscopy, imaging tests
• Treatment: Surgery, radiation therapy, chemotherapy, targeted drugs

• Common symptoms: Weight gain, sensitivity to cold, thinning hair, depression, enlarged thyroid
• Confirmation tests: Thyroid panel blood test
• Treatment: Hormone therapy

• Common symptoms: Excessive bleeding, deep bruising, bloody stool
• Confirmation tests: Coagulation panel blood test
• Treatment: Replacement therapy, desmopressin hormone, clot-preserving medication, physical therapy

• Common symptoms: Abdominal pain, dark urine, joint pain, jaundice
• Confirmation tests: Further blood tests, transient elastography, liver biopsy
• Treatment: Rest, antiviral medication, interferon injection, liver transplant

• Common symptoms: Weight loss, abdominal pain, jaundice, white stools
• Confirmation tests: Imaging tests, liver biopsy
• Treatment: Surgery, liver transplant, radiation therapy, targeted drug therapy, chemotherapy

• Common symptoms: Painful urination, abdominal pain, vaginal or penile discharge
• Confirmation tests: Urine test, swab test
• Treatment: Antibiotics

• Common symptoms: Abdominal pain, fever, rapid pulse
• Confirmation tests: Stool test, CT scan, ultrasound, MRI
• Treatment: Fasting, pain medication, IV fluids

• Common symptoms: Severe abdominal pain, nausea, fever
• Confirmation tests: Imaging tests, hepatobiliary iminodiacetic acid scan
• Treatment: Fasting, IV fluids, antibiotics, pain medication, endoscopic retrograde cholangiopancreatography

• Common symptoms: Weakness, pale skin, irregular heartbeat, chest pain, cold hands and feet
• Confirmation tests: Complete blood count test
• Treatment: Nutritional supplements, blood transfusion

• Common symptoms: Bone pain, nausea, constipation, excessive thirst, weakness in legs
• Confirmation tests: Blood test, urine test, bone marrow aspiration, imaging tests
• Treatment: Drug treatment, chemotherapy, corticosteroids, bone marrow transplant, radiation therapy

• Common symptoms: Excessive coughing, coughing up blood, chest pain, weight loss
• Confirmation tests: Skin test, blood test, imaging tests, sputum tests
• Treatment: Medication

Hematology– the study of blood — has improved dramatically in recent years. In the past two years alone, the U.S. Food and Drug Administration has approved blood tests that can detect signs of concussion, menopause, and the Ebola virus.

One of the most commonly ordered blood tests is a complete blood count, which measures different blood cell levels and can help detect warning signs for conditions like anemia, infections, blood cancers, and immune system disorders. Another common test is the coagulation panel, which measures blood clots and can help diagnose leukemia, hemophilia, and thrombosis.

The basic metabolic panel is a group of tests that measure different chemicals in the blood and can give doctors information about blood sugar levels, bones, and heart, kidneys, and liver functions. Another common test is the lipoprotein panel, which tests such substances in the blood as cholesterol and can help show the risk for coronary heart disease. There are many more tests that are used when doctors need to investigate further.

To identify life-saving blood tests that reveal serious health conditions, 24/7 Tempo conducted a review of various medical publications such as the nonprofit Mayo Clinic, the U.S. National Library of Medicine, and the U.S. Food and Drug Administration press announcements.

We chose conditions for which blood tests can either confirm the presence of the disorder or help identify warning signs that prompt further confirming tests. Information on symptoms, confirming tests, and treatment came from the Mayo Clinic and other sources.