Lab Testing FAQs > Types of Lab Tests

Lab tests are a type of common medical procedure that can be used to provide insights about a patient’s health. There are many categories of lab tests; some focus on specific organs or body systems, while others test for the presence or absence of various substances. Some tests simply measure the level of chemical components in body fluids or tissues.

Categories of Lab Tests

Lab tests can be grouped into several broad categories based on their purpose and the types of insights they provide. Some lab tests are diagnostic—meaning they help detect the presence or absence of certain diseases or conditions—while others provide general information about body systems. 

Come of the most common categories of lab tests include:

  • Organ function tests (Examples: BUN, bilirubin, creatinine)
  • Screening tests (Examples: complete blood count, pap smear, urinalysis)
  • Infectious disease tests (Examples: flu, strep throat, mononucleosis)
  • Sexually transmitted infection tests (Examples: chlamydia, gonorrhea, HIV)
  • Tumor and cancer marker tests (Examples: CA 125, PSA, AFP, CEA)
  • Inflammatory and autoimmune tests (Examples: ANA, CRP, RF)
  • Nutrient and vitamin level tests (Examples: calcium, magnesium, B12, vitamin D)
  • Hormone level tests (Examples: cortisol, testosterone, follicle stimulating hormone)
  • Cholesterol level tests (Examples: HDL, LDL, triglycerides)

Some of these lab tests are prescribed annually by doctors in order to maintain an accurate picture of the patient’s health over time. For instance, pap smears and complete blood counts are often conducted during yearly physical exams.

Other tests are ordered when a patient is experiencing certain symptoms, to help rule out or diagnose various conditions or illnesses. These include STI tests, infectious disease tests, and autoimmune tests.

Lab tests can also be used to monitor the effectiveness of medications and ongoing treatment plans. For instance, tumor marker tests may be ordered to track a cancer patient’s treatment progress.

Types of Lab Test Specimens

Modern medical technologies allow lab technicians to test a wide and diverse range of specimens. The most common types of lab tests rely on samples that are easily collected from bodily fluids or tissues. However, there are certain tests that require minor surgery and anesthesia in order for the specimen to be collected.

Examples of specimens that can be collected and tested in a lab include:

  • Naturally eliminated fluids (typically collected in a sterile cup)
    • Urine
    • Stool
    • Saliva
    • Sputum (phlegm or mucus coughed up from the respiratory tract)
    • Semen
  • External body tissues
    • Skin biopsy
    • Hair
    • Fingernails
  • Internal body fluids and tissues
    • Blood
    • Cerebrospinal fluid
    • Needle biopsy
    • Organ biopsy
    • Bone marrow
  • Swabs
    • Vaginal secretion swabs
    • Nasal or throat swabs
    • Wound swabs

Some specimens—such as urine, stool, and saliva—are collected by the patient and handed off to a healthcare provider or lab technician. In certain cases, these samples may even be collected at the patient’s home. Other specimens—such as swabs and blood tests—are collected by a skilled medical worker in a clinic or laboratory setting.