Nurse taking vital signs with patient at medhelp

Your Guide to Primary Care Lab Tests

Nov 15, 2021 Family Medicine Share:

In our last article, we discussed the three most common lab tests used by urgent care doctors. And while lab tests are a really useful diagnostic tool in an urgent care setting, primary care doctors also use labs to provide better care to their patients.

Why do primary care doctors order lab tests?

Just like an urgent care doctor, your primary care doctor can use laboratory testing to diagnose your current acute issues. In fact, if you have a primary care doctor, you should always try to schedule your sick visits with them first. (Urgent care is a great option if your primary care doctor is unavailable for a sick visit.) Your primary care doctor can also use diagnostic testing to identify other issues that may not present with obvious symptoms, such as diabetes or high cholesterol.


Because your primary care doctor wants to keep you healthy, preventive medicine is a key part of your care. One way your doctor does this is through regular screenings. Early detection can allow for simpler and effective treatment. For example, if your doctor discovers through lab tests that you have high cholesterol, you can begin to make lifestyle changes and take medication to lower your cholesterol. Undetected and unchecked, high cholesterol can lead to heart disease or even a heart attack.

Your primary care doctor may also choose to screen you regularly for potential medical issues based on your personal and family medical history. For example, if you have a family history of diabetes, your doctor may regularly order tests to monitor key markers for diabetes such as blood glucose and A1C. Many of these screening tests can be done in your doctor’s office. Your doctor may also recommend other screenings such as a colonoscopy or a mammogram.


By running lab tests annually, your primary care doctor can monitor changes in your lab data over time. While one lipid panel may show that your cholesterol is in a normal range, three years of data may show that your cholesterol is creeping higher. Your doctor will also look at changes in your weight, blood pressure, and other key labs over time and note anything that deviates from your normal.

If you have one or more chronic conditions, your primary care doctor will want to monitor your health through regular exams and lab work. Lab tests can help your doctor be sure that your medication or treatments are staying effective. Changes in your labs or symptoms may also indicate the need to bring in a specialist to help with your care.

Common lab tests used by primary care doctors

Your primary care doctor will use many of the same tests an urgent care doctor will use, including complete blood count and urinalysis. These can be used as diagnostic tools or as useful screening tools in a primary care setting.

Primary care doctors will also use several other common lab tests for screening and monitoring. The following tests are the most commonly used, routine tests used by primary care doctors, but this list is not exhaustive. Other tests may be ordered based on your healthcare needs.

Vital Signs

Whenever you visit a doctor, whether you’re there for an urgent care or a primary care visit, a nurse will take your vital signs. While your vital signs aren’t technically a lab test, they provide valuable information to your primary care doctor. These are especially helpful when they’re read over a period of time.

Your vital signs include:

  • Height
  • Weight
  • Temperature
  • Pulse rate
  • Respiration rate
  • Blood pressure

While your adult height typically won’t change, your other vital signs will fluctuate from visit to visit. Some of these changes may be slight, and some of them may be more noticeable. But even slight changes over time can have a significant impact on your health. For example, you might not notice that your blood pressure is getting a little higher each year, but your doctor will.

Basic and Comprehensive Metabolic Panel

Your primary care doctor may choose to order either a basic or a comprehensive metabolic panel, depending on your needs. The basic panel tests eight substances in your blood and gives information to your doctor about how your body uses energy. (The comprehensive panel tests these same 8 substances, as well as six additional substances.)

The basic panel is primarily used by doctors to analyze how you metabolize sugar, determine the health of your kidneys, and also look for electrolyte imbalances. The basic panel is a great screening tool for diabetes, and it can even show if you’re dehydrated.

The comprehensive panel will provide this same information to your doctor, but it also provides more information about how well your liver is functioning.

Either metabolic panel provides valuable information to your primary care doctor since many of the issues that might be detected with this panel won’t have outward symptoms until the condition has progressed significantly.

Lipid Panel

A lipid panel measures the amount of cholesterol in your blood. This test is a simple blood test that’s taken from a vein in your arm. Results from a lipid panel will include information about HDL, LDL, and triglycerides.

HDL (or high-density lipoprotein) is also known as “good cholesterol”. This is the type of cholesterol where it’s good to have a high number. HDL helps your body remove other types of cholesterol from your body. High HDL can actually lower your risk of heart disease and stroke.

LDL (or low-density lipoprotein) is the cholesterol your doctor wants to watch. High LDL can increase your risk of heart disease. LDL can build up in your blood vessels and, as it builds up over time, can lead to a narrowing of your blood vessels. Fortunately, you can potentially lower your LDL with simple lifestyle interventions and medication before it leads to heart disease or stroke.

Triglycerides are a specific type of fat in your blood. Unused calories are converted into triglycerides and stored in your fat cells for use. High triglycerides have also been linked to heart disease.

It’s impossible to see cholesterol problems without laboratory testing. But through early testing and detection, you can be proactive and lower your risk of heart disease and stroke.

Thyroid Panel

A thyroid panel evaluates how well your thyroid is functioning. Your thyroid is a butterfly-shaped gland that’s located at the front of your neck and produces regulatory hormones. If your thyroid is functioning poorly, it can have a significant impact on weight, mood, sleep, digestion, and energy.

Hypothyroidism (underactive thyroid) and hyperthyroidism (overactive thyroid) are common culprits for many health complaints. A thyroid panel is a great screening test if you’re seeing new symptoms that don’t have another explanation. For example, if you haven’t changed your diet or exercise habits but have gained some weight since your last visit, your doctor may order a thyroid panel to ensure that your thyroid is functioning properly.

Thyroid issues can easily be treated with prescription medication.


A1C, or HbA1C, is also known as glycated hemoglobin. This test shows how well you’re managing your blood sugar and gives your primary care doctor a picture of your average blood sugar over the last 8 to 12 weeks. This test is different from a blood glucose test, which gives a snapshot of your current blood glucose level.

A high A1C reading indicates that your blood sugar is poorly controlled. Your primary care doctor can use an A1C test to screen for diabetes as well as monitor how well diabetes treatment is going.

Vitamin D

Vitamin D is an essential vitamin that your body needs for a number of functions, including calcium absorption, regulation of your immune system, and protecting the health of your bones, muscles, and heart. However, many people just don’t get enough vitamin D. Vitamin D deficiency can be responsible for fatigue, depression, muscle aches or pains, weight gain, and low immune function.

Your primary care doctor can test for vitamin D deficiency with a simple blood test.. If you’re severely deficient in vitamin D over a long period of time, you may begin to suffer from bone density loss; this can lead to osteoporosis and a risk of more frequent fractures.

It’s difficult to get vitamin D from your diet, and sunlight exposure may not be sufficient to overcome a deficiency. Prescription vitamin D supplements can help.

What to expect after your primary care doctor orders lab tests

While all of these lab tests are performed in just a few minutes, you usually won’t know the results right away. Your primary care doctor will let you know when to expect your results, but most results are ready in a week or so.

At MedHelp, lab results are loaded to your patient portal. A nurse will also call you to let you know if your results are all normal. Your doctor will discuss any abnormal results with you and will let you know if further treatment or testing is needed. You may need to schedule a follow-up appointment.

While no one really enjoys lab tests, they’re an essential part of keeping you well. Your primary care doctor is your advocate for better health and is there for you if you have questions. You can always ask your doctor why they’re choosing to run a particular test or what a specific test result means.

At MedHelp, we don’t just offer primary care services. We provide relationship-based primary care, which means that your primary care doctor becomes your long-term partner for better health.

Need a partner for better health?

Primary care doctors at each MedHelp location are accepting new patients. We can help you choose a doctor that meets your needs.