Version July 2025
| Condition | When to consider testing | What initial tests to order | Test characteristics |
| Endocrine abnormalities | |||
| Hyperthyroidism | Associated symptoms of heat intolerance, palpitations, anxiety, weight loss, increased frequency of bowel movements | TSH | Sensitivity 86 to 95%, specificity 92 to 95% |
| Free thyroxine (T4) | Sensitivity 82%, specificity 94% | ||
| Alteration in estrogen or androgen levels (such as menopause, male hypogonadism) | Women: Consider age, menstrual history, surgical status, symptoms of night sweats, hot flashes, and vaginal dryness | Clinical diagnosis; routine measurement of FSH not recommended Exceptions: Obtaining FSH level is recommended for women with underlying menstrual irregularities (such as polycystic ovarian syndrome), history of hysterectomy or endometrial ablation, and age <40 years | N/A |
| Men: History of androgen deprivation therapies (surgical or chemical), decreased libido, decreased spontaneous erections, erectile dysfunction | Morning fasting testosterone level | Normative range for testosterone levels varies among assays. Low testosterone levels should be confirmed on at least 2 morning blood samples. | |
| Infectious disease | |||
| Active pulmonary tuberculosis | Respiratory symptoms with appropriate risk factors (such as person living with HIV, known active tuberculosis contact, residence in a country with high incidence of disease, travel to endemic regions) | Chest radiography | Any abnormality: Sensitivity 94%, specificity 89% Abnormality suggestive of pulmonary tuberculosis: Sensitivity 85%, specificity 96% |
| Sputum for Mycobacterium tuberculosis nucleic acid amplification test | Xpert: Sensitivity 85 to 88% (98% for AFB smear positive and 67% for AFB smear negative), specificity 96 to 98% | ||
| HIV/AIDS | Not tested for HIV in past or prior negative test but subsequent high risk of exposure (such as multiple sexual partners, injected drug use) | Symptoms >2 weeks: Current-generation antibody/antigen testing | Fourth-generation antibody/antigen (screening in patients in high-prevalence population): Sensitivity 79.8%, specificity 99.9% |
| Symptoms <2 weeks: Current-generation antibody/antigen testing and HIV viral load | HIV quantitative viral load (symptoms consistent with primary HIV): Sensitivity 100%, specificity 97.4% | ||
| Endocarditis or occult bacteremia | Presence of concurrent fevers, new cardiac murmur, embolic stigmata in extremities | Blood culture | 1 set: 73 to 80% sensitivity for bacteremia, may be more sensitive in endocarditis |
| Hematology/oncology | |||
| Acute leukemia | Bleeding, spontaneous bruising | Peripheral blood smear | No published test characteristics of peripheral smear |
| Chronic myeloid leukemia | Splenomegaly, early satiety | Complete blood count with differential | Absolute basophil count ≥0.43 × 109/L: Sensitivity 93.9%, specificity 95.2% |
| Lymphoma | Lymphadenopathy, weight loss | LDH | ≥2 time above upper limit of normal: Sensitivity 56%, specificity 85% |
| Cross-sectional imaging (CT torso or PET) | CT torso: Sensitivity 70%, specificity 100% PET/CT: Sensitivity 99%, specificity 100% | ||
| Solid organ malignancy | Localizing symptoms, weight loss, personal or first-degree relative with history of malignancy | Cross-sectional imaging (CT torso) | Difficult to quantify test characteristics for solid malignancies in general |
| Disease-specific tumor markers (PSA for prostate) | Sensitivity 93%, specificity 20% | ||
