A patient is losing weight, without trying. We worry about Infections if going on a few weeks, about Cancers if going on longer.
We approach this as follows (see Full Text for explanation of the various parts of the work-up):
1. Take a medical history, looking for clues like:
- Diarrhea (significant): likely explanation (see topic Diarrhea for work-up & causes)
- Blood (coughing it, vomiting it, pooping/peeing it, etc): investigate the organ it’s coming from (lungs, stomach, bowel, bladder, etc.)
- Symptoms pointing to a specific organ (trouble swallowing, hoarseness, pain, etc.): investigate that organ (endoscopy, x-ray / images, biopsies, etc.)
- Nausea / Vomiting: if all tests normal, might be a Stomach Ulcer (refer for endoscopy, or try treating it)
- Sweats at night (drenching) — could be Infection or Cancer. Needs tests in #3 below, maybe CT scan of abdomen & pelvis
- New Lump or Mole, or changes in previous one — suspect Cancer. Biopsy it.
2. Perform a Physical Exam, looking for clues like:
- One swollen lymph node (gland): biopsy it for Cancer; Infection
- Lots of swollen lymph nodes (glands): biopsy, lab tests (see below)
- A lump (breast, thyroid, testicle, etc): biopsy it (or refer to appropriate specialist)
- Jaundice (eyes yellow): labs for liver function; CT scan for Cancer of Pancreas or Gallbladder
- Large liver or spleen: lab tests, CT scan of abdomen (for Cancers)
- Fever (by thermometer): Likely Infection or Cancer. Needs tests as in #3 below, likely CT scans of abdomen & pelvis too.
3. Order basic Laboratory Tests like:
- Complete Blood Count (CBC)
- Erythrocyte Sedimentation Rate (ESR, Sed Rate) / C-Reactive Protein (CRP)
- If very high, may mean Cancer, certain Infections
- Thyroid Stimulating Hormone (TSH) (thyroid blood test) — for Hyperthyroidism
- Comprehensive Metabolic Panel (CMP) blood tests, which include:
- Glucose (sugar): For Diabetes (very high sugar can cause weight loss)
- Liver function tests: Acute Hepatitis, or Cancer (of liver, or metastases from elsewhere)
- Albumin low: Maybe Cancer somewhere
- Calcium high: Due to some Cancers (see Full Text for relationship to albumin)
- Creatinine high: Kidney Failure, maybe Multiple Myeloma (a blood cancer)
- Globulin high: Chronic Infection (like HIV, Hepatitis B or C), maybe Multiple Myeloma
- Serum & Urine Protein Electrophoresis — for Multiple Myeloma & other blood Cancers
- Lactose Dehydrogenase (LD; LDH) — blood test increased with various Cancers, Lung Diseases
- HIV Test — for HIV
- Prostate Specific Antigen (PSA) in man >50 y.o. (if African-American >40) — for Prostate Cancer
- Urinalysis — blood in urine may be kidney or bladder cancer
- CT scan for Kidney Cancer; Urology referral for cystoscopy for Bladder Cancer
- Chest X-Ray — for Lung Cancer; various other Lung Diseases
4. If any Upper Abdominal Pain, or Nausea / Vomiting, we may try treatment with high-dose Proton Pump Inhibitor (PPI) for possible stomach ulcer (see Antacid Medicines).
- If it helps symptoms, lower to standard dose
- BEWARE: PPI’s can relieve the pain of stomach cancer. We’d change soon to an “H-2 Blocker” (also cure ulcers but won’t help cancer pain) (see Antacid Medicines).
- If pain returns, or weight doesn’t improve rapidly, we refer to Gastroenterologist for Endoscopy to rule-out Stomach Cancer.
5. If None of the Above (no symptoms suggesting possible Ulcer, and all of history, physical exam, & lab tests are normal), we explore the possibility of various psychiatric disorders, especially Depression
6. Everything is Normal — if weight still declines during 2-3 weeks from initial visit, patient needs bigger work-up (for various Cancers):
- Abdominal and Pelvic CT scans
- Colonoscopy if the patient is over 45 and hasn’t had one recently (for Colon Cancer)
- Mammogram if over 40 & no recent exam (for Breast Cancer)
- If signs of very rare Adrenal Insufficiency (new tanning of skin; or a drop in blood pressure between lying down & abrupt standing) — refer to an Endocrinologist
See Weight Loss — Full Text for more in-depth explanations and discussions.