Lab Testing Services in Maryland: What Your Blood Work and Diagnostic Tests Mean

A lab test is one of the most common things a doctor orders, and one of the least understood. You might get a call asking you to stop by for blood work, or a printout full of numbers and little abnormal flags, with no explanation of what any of it means. Lab results make the most sense when you know why a test was ordered and what your provider expects you to do next.

If you're looking for lab testing services, the diagnostic testing page at Maryland Behavioral Health describes what's available. For background on the broader practice, the family medicine services page explains how routine testing fits into primary care.

Why Doctors Order Lab Tests

Lab tests serve several purposes. They can help diagnose a condition when symptoms aren't clear, screen for problems before symptoms appear, track how a chronic condition is responding to treatment, or check how a medication is affecting your body. A test ordered during a routine physical might look for anemia or check your cholesterol. A test ordered during an illness might look for an infection. Your provider chooses tests based on your history, symptoms, and risk factors.

A single result rarely tells the whole story. Doctors usually interpret lab values alongside your symptoms, your history, and other results. A number that's slightly outside the reference range may mean nothing for you, or it may matter a lot. That's why it helps to ask your provider what a result means for you specifically.

Types of Testing You Might Encounter

Blood tests are the most common. A basic metabolic panel checks blood sugar, kidney function, and electrolytes. A complete blood count looks at red and white blood cells and platelets. A lipid panel measures cholesterol and triglycerides. A hemoglobin A1c shows average blood sugar over the past few months. Your provider may also order urine tests, thyroid tests, or screening for infections.

Imaging such as X-rays or ultrasounds isn't a lab test, but it's often ordered alongside lab work.

Fasting and Preparation

Many routine tests don't require any preparation at all. Common blood tests such as a complete blood count or thyroid tests usually don't need fasting. Some blood sugar and cholesterol tests do, and when fasting is required it typically means no food or drink other than plain water for a set period, often 8 to 12 hours. Whether fasting applies depends on the specific tests ordered, so follow your ordering provider's instructions for your visit. If you're unsure, ask before you go rather than guessing.

Don't stop taking prescribed medication before a test unless your provider tells you to. Ask whether it's okay to take your usual medicines and supplements on the day of the test, since some tests may call for a temporary change.

How Testing Labs Are Regulated

Laboratories that perform testing on human specimens to help diagnose, prevent, or treat disease generally need to meet applicable CLIA requirements. The Clinical Laboratory Improvement Amendments of 1988 set quality standards so that test results are accurate, reliable, and timely, and the Centers for Medicare & Medicaid Services runs the program. The requirements depend on the types and complexity of tests performed. Waived tests, which are simpler, have different requirements from more complex testing. Facilities that only collect or prepare specimens are generally not considered laboratories under CLIA. Some states operate their own approved programs, so details can vary by location.

CLIA certification is a useful signal when you're choosing where to have tests done. If a lab doesn't mention it, ask.

Getting Your Results

You have a right to your lab results. Under the HIPAA Privacy Rule, patients can request copies of their health information, including completed lab reports, and in most cases those copies must be provided within 30 days of the request. A 2014 federal rule also requires CLIA-certified labs to give patients access to completed test reports on request, in addition to whatever your doctor shares.

Ask your provider how results will be shared with you, whether through a patient portal, a phone call, or a visit. If you're waiting on results and haven't heard back, call the office. Don't assume that no news means normal results.

Reading a Lab Report

Most reports list each test, your result, a reference range, and sometimes a flag marking a value as high or low. Reference ranges can vary between labs, so compare results against the range on your own report. A flag is a starting point, not a diagnosis. Your provider can explain whether a value needs follow-up, a repeat test, or no action at all.

Keep copies of your results over time, since trends often matter more than a single number.

Testing and Medications

Some medications require routine lab monitoring. Your provider may check kidney function, liver enzymes, electrolytes, or blood counts to make sure a medication is safe for you. If you take a prescribed medication for a mental health condition, the medication management care page describes how prescriber follow-up typically works, including when labs may be part of that plan.

Testing for Substance Use

Some providers use urine or other drug screens as part of substance use care. These tests can help your care team understand what's happening and adjust treatment. They are not meant as punishment. If you've been asked to take one and have questions about what it's for, ask before you go. Our substance use disorder treatment page explains how testing fits into recovery-focused care.

Questions to Ask Before a Test

Ask why the test is being ordered and what you'll learn from it. Ask whether you need to fast or change anything before the draw. Find out how long results usually take and who will contact you. Ask whether your insurance covers the test and what you may owe, since costs can vary widely between labs. If you've been referred to an outside lab, confirm that it's in your plan's network.

If Something Feels Wrong

Lab results are rarely a reason for panic, but some symptoms should not wait for a scheduled test. Chest pain, severe shortness of breath, fainting, or signs of a stroke need emergency care right away, so call 911. If you're having thoughts of harming yourself, call or text 988 at any time to reach the Suicide and Crisis Lifeline.

Getting Started

Lab testing works best when you understand it. Ask why each test is ordered, follow the preparation instructions, and bring any confusing results to your next visit.