Which blood tests should you get for your symptom?
Each page explains the common, testable causes of one symptom, which tests look for them and what they cost, and — first — the situations where a lab order is the wrong step and a clinician or emergency care is the right one. Educational, not a diagnosis.
What blood tests should you get for fatigue?
Persistent fatigue has a short list of common, testable causes: an underactive thyroid, low iron stores, vitamin B12 or D deficiency, and blood-sugar problems.
Which blood tests help explain brain fog?
Brain fog — poor concentration, slow recall, mental fatigue — is commonly linked to thyroid dysfunction, vitamin B12 deficiency, low iron, blood-sugar swings and low vitamin D.
What blood tests should you get for hair loss?
Diffuse hair shedding is often driven by something measurable: low iron stores (ferritin), thyroid dysfunction (TSH), hormone shifts (testosterone, DHEA-S, SHBG) and low vitamin D or zinc.
What blood tests check for causes of unexplained weight gain?
When weight climbs without a change in eating or activity, the testable causes are an underactive thyroid, insulin resistance and cortisol excess.
Which blood tests are used for unexplained weight loss?
Losing weight without trying deserves a prompt, broad look: an overactive thyroid, diabetes, celiac disease and chronic inflammation are the common testable causes.
Why am I always cold? Blood tests that check the common causes
Feeling cold when others are comfortable is a classic hypothyroid symptom and a common sign of anemia or low iron.
What blood tests are used for joint pain?
Blood tests sort joint pain into inflammatory, autoimmune and metabolic causes.
Can blood tests find a physical cause of anxiety?
Sometimes.
What blood tests are worth checking for insomnia?
Sleep problems have a few measurable contributors: a disrupted cortisol rhythm, thyroid dysfunction, low ferritin (linked to restless legs) and low magnesium.
Which blood tests check for causes of low libido?
Low sex drive is often hormonal and often testable: total and free testosterone (in men and women), SHBG, estradiol, prolactin and thyroid function are the standard set.
What blood tests are used for muscle weakness?
Muscle weakness with no obvious cause is checked with creatine kinase (muscle breakdown), a comprehensive metabolic panel (electrolytes, kidney and liver), magnesium, vitamin D, TSH and morning cortisol.
Which lab tests help with chronic bloating?
Chronic bloating with diarrhea, fatigue or weight change deserves a celiac screen (tTG-IgA with total IgA), a CBC and iron studies for the malabsorption it can cause, and stool calprotectin when inflammatory bowel disease is a concern.
What blood tests help explain dry skin, acne and rashes?
Persistent skin changes sometimes have a systemic cause blood tests can find: dry, coarse skin with hypothyroidism; adult acne with androgen excess or PCOS; itching with liver, kidney or iron problems; and slow healing with high blood sugar or low zinc.
What blood tests check the causes of frequent urination?
Frequent urination with thirst is a classic sign of high blood sugar, so hemoglobin A1c and fasting glucose come first, with a urinalysis to check for infection, glucose and protein and a metabolic panel for kidney function and calcium.
Which blood tests are used for irregular periods?
Irregular or missed periods are evaluated with the hormones that run the cycle — FSH, LH, estradiol and progesterone — plus prolactin, TSH and androgens (testosterone, DHEA-S), which cover the common disruptors: PCOS, thyroid disease, high prolactin and perimenopause.
What blood tests are used for erectile dysfunction?
Erectile dysfunction is often the first sign of a vascular or metabolic problem, so the workup checks more than testosterone: total and free testosterone with SHBG, hemoglobin A1c and glucose, a lipid panel, TSH and prolactin.
What blood tests check for causes of numbness and tingling?
Tingling in the hands or feet has two very common testable causes: vitamin B12 deficiency and diabetes-related nerve damage.
Which blood tests are used for shortness of breath?
Breathlessness on exertion that builds over weeks is checked for anemia (CBC, ferritin, iron studies), heart strain (NT-proBNP) and thyroid disease (TSH).
What blood tests are used for easy bruising?
Bruising more easily than usual is checked with a CBC (platelet count), prothrombin time/INR (clotting factors), a comprehensive metabolic panel (liver function, since the liver makes clotting factors), and vitamin C, whose deficiency weakens blood vessels.
What blood tests check for causes of night sweats?
Night sweats are most often hormonal — perimenopause and menopause in women, low testosterone in men — or thyroid-related, and those are testable: FSH, LH, estradiol, TSH with Free T4, and a CBC.
Can blood tests explain mood swings and irritability?
Sometimes.
What blood tests are used for heart palpitations?
Palpitations that come and go are commonly linked to an overactive thyroid, anemia, and low potassium or magnesium — all checked with TSH and Free T4, a CBC, a metabolic panel and magnesium.
Which blood tests check for causes of dizziness?
Lightheadedness — especially on standing — is checked for anemia (CBC, ferritin), low or high blood sugar (glucose, A1c), dehydration and electrolyte problems (metabolic panel), thyroid disease (TSH) and vitamin B12 deficiency.
What blood tests check for excessive thirst?
Constant thirst with frequent urination is the textbook presentation of high blood sugar, so hemoglobin A1c and fasting glucose lead, with a comprehensive metabolic panel for sodium, calcium and kidney function and a urinalysis.
What blood tests are used for swollen ankles and legs?
Swelling in both legs is checked for the organ causes — kidney (creatinine, eGFR, urine protein), liver (albumin, liver enzymes), heart (NT-proBNP) and thyroid (TSH) — with a comprehensive metabolic panel, urinalysis, NT-proBNP and TSH.
Which blood tests should you get for frequent headaches?
Most headaches are migraine or tension-type and no blood test diagnoses them, but labs catch the treatable contributors: anemia, thyroid disease, dehydration and electrolyte shifts, low vitamin D or B12, high blood sugar, and — in adults over 50 with a new headache — inflammation (ESR/CRP).
Which blood tests help explain chronic constipation?
Chronic constipation is usually diet, fluid, activity or medication related, but blood tests catch the metabolic causes worth excluding: an underactive thyroid (TSH), high calcium and low potassium or magnesium (metabolic panel), diabetes (A1c), and celiac disease.
Which blood tests should you get for ongoing nausea?
Persistent nausea has many causes, and a first round of blood tests covers the ones labs can see: liver and pancreas (hepatic panel, lipase), kidney function and electrolytes, blood sugar, thyroid, anemia and — in anyone who could be pregnant — hCG.
Which blood tests should you get for adult or hormonal acne?
Adult acne — especially along the jawline, flaring before periods, with irregular cycles or excess hair — often has a hormonal driver labs can measure: total and free testosterone, DHEA-S, SHBG, and LH/FSH for PCOS, with fasting insulin and A1c because insulin resistance raises androgens.
Which blood tests confirm hot flashes are from menopause?
Hot flashes after 45 with changing periods are almost always perimenopause, and no test is required to diagnose it — but labs help when the picture is unclear or you are under 45: FSH and estradiol (interpreted with cycle timing), TSH because an overactive thyroid mimics menopause, and AMH for ovarian reserve.
Which blood tests should you get for frequent muscle cramps?
Most muscle cramps are benign — exertion, dehydration, pregnancy, age — but frequent or night-time cramps justify checking electrolytes and minerals (potassium, sodium, calcium, magnesium), kidney and liver function, thyroid, blood sugar and vitamin D, plus creatine kinase if muscles are also weak or sore.
Which blood tests should you get for heavy periods?
Heavy periods do two things labs can see: they drain iron, and they can signal a hormone or clotting cause.
Which blood tests should you get for dry skin and brittle nails?
Dry skin and brittle, ridged or spoon-shaped nails are common and usually environmental, but they are also classic signs of an underactive thyroid, iron deficiency, and low zinc, vitamin D or biotin — and, less often, diabetes or kidney and liver disease.
Which blood tests should you get for restless legs?
Restless legs syndrome has one lab that changes management: ferritin.
Which blood tests should you get for itching without a rash?
Itching all over without a visible rash is the presentation where blood tests earn their keep: liver disease (bile-salt itch), kidney disease, iron deficiency, thyroid disorders, diabetes, and blood conditions such as polycythemia and lymphoma can all cause it.