Blood Work Basics: What You Need to Know to Improve Your Health
Medically Reviewed by Dr. Parris Kidd

When was the last time you got your blood work done?

In the past, some doctors recommended getting blood work done in conjunction with an annual physical. Depending on your genetics and current state of health, you may need to have a blood draw more frequently, especially if advised by your healthcare professional.

Blood Work Basics

Since you can’t change what you don’t measure, having important health indicators at optimal levels is critical to brain and body function. To help with emotional and physical well-being, be sure to periodically check your:

  • Body mass index (BMI) – as your weight goes up, your brain function can go down
  • Blood pressure (BP) – as your BP goes up, it can damage blood vessels and negatively affect the functioning of your brain
  • Other key laboratory tests that can affect your brain and body – these should include CBC (complete blood count), general metabolic panel, and other specific test numbers.

Let’s look at each of these blood work basics…

Body Mass Index

This measurement is the result of comparing weight to height.

  • Optimal BMI is between 18.5 and 25
  • Overweight range falls between 25-30
  • Obese range falls between 30-39
  • Morbidly obese is 40 or more

To determine your BMI, you can search online for a “BMI Calculator” and fill in your height and weight. Take this number seriously.

Being overweight increases the risk for serious mood and memory issues, as well as problems with your heart and circulation, joints, and all your other organ systems.

Blood Pressure

Another of the blood work basics is blood pressure. Good blood pressure is critical for brain health.

High blood pressure is associated with lower overall brain function, which can lead to bad decision-making and other mental difficulties. Low blood pressure means your brain and other organs may not be getting enough blood to function at their best.

The American Heart Association and the American College of Cardiology have revised their guidelines, which now means anyone with a BP of 130/80 millimeters of mercury will be diagnosed with Stage 1 hypertension. Previously, a blood pressure of 140/90 was considered hypertension (the category of “prehypertension” no longer exists).

This means more Americans than ever – half of all men and 38% of women, or 103 million people versus 72 million before this change – are now considered to have hypertension.

Here are the BP numbers you should know:


  • Systolic 90-120
  • Diastolic 60-80

Stage 1 Hypertension

  • Systolic 130-139
  • Diastolic 80-89

Stage 2 Hypertension

  • Systolic >/= 140
  • Diastolic >/= 90

Hypotension (low BP)

  • Systolic < 90
  • Diastolic < 60

Blood Work 2 Key Laboratory Tests

In addition to the blood work basics detailed above, laboratory tests can provide important numbers. Ask your healthcare professional to order them, or you can order them yourself at websites like

If your numbers are less than ideal, be sure to work with your physician or other qualified healthcare practitioner to get them into optimal ranges. Here are just a few of the key lab tests, plus additional tests, that can provide insights into how well your body is functioning.

Complete Blood Count (CBC)

This blood test many physicians check first. It gives insight into the health of your bone marrow and other organs that produce your red and white blood cells. This test can reveal a great deal about your overall state of health.

Low red cell count (anemia) can make you feel anxious and tired, and lead to memory problems. Enlarged red cells may mean you’re drinking too much alcohol.

High white cell count may indicate infection. The proportions of the different white cell types can give useful information on the health of your immune system.

General Metabolic Panel

This panel checks the health of your liver and kidneys, as well as your fasting blood sugar and blood lipids – cholesterol and triglycerides – which, if high, can increase your risk for a heart attack.

Why is high fasting blood sugar a problem? Over time, it can generate substances called glycates, which can cause circulatory (blood vessel) problems throughout your whole body, including your brain. Over time, these glycates can damage the vessel walls and make them vulnerable to breaking.

Glycates from high blood sugar also can attack nerve cells. These include the electrically active vision-sensing cells of the retina at the back of the eye (retinal neuropathy), and nerve networks in the arms and legs (peripheral neuropathy).

Long-term, the glycates from high blood sugar also can impair immunity and slow the healing of wounds, cause premature wrinkling of the skin, and likely contribute to cognitive problems.

Hemoglobin A1c, or HbA1c

This test measures the blood levels of a glycate formed between sugar and hemoglobin. It’s especially valuable for diabetics because it’s a long-term measure of the average blood sugar levels for the prior two to three months, not just a short-term measure since these numbers are notoriously variable.

Blood Lipids: Cholesterol and Triglycerides

Abnormally high levels of cholesterol and/or triglycerides in the blood are important health measures, especially since they can cause atherosclerotic blood vessel disease that results in lowered blood delivery to the brain.

LDL (low-density lipoprotein) cholesterol can be bad for the brain when levels are high. It’s important to know the particle size of your LDL cholesterol (ask your healthcare professional to order this test). Smaller LDL particles are more toxic than larger ones – they’re more able to penetrate the walls of blood vessels and cause or contribute to atherosclerotic plaque in the vessel wall.

The type of cholesterol called HDL (high-density lipoprotein) can be protective for the circulatory system and for the brain. Regular exercise can raise HDL and lower LDL. Both these forms of cholesterol are essential to our health, but we need them to stay within normal ranges.

C-reactive protein (CRP)

This test is a useful measure of inflammatory activity in your body. Inflammation comes from the Latin word for “to set on fire.” Inflammation that continues long-term has been linked to many serious illnesses, including mood and other brain-related brain problems, heart and circulatory problems, liver problems, joint pain, and a variety of problems with other organs.

CRP is a good indicator of long-term inflammation and can be elevated if you’ve had a cold or recent injury. Be sure to inform your practitioner if you were having these issues when you got the CRP test.

Homocysteine (HC)

This is a substance produced by our normal metabolic activity. In healthy people, it’s recycled as it’s generated and doesn’t reach high levels in the blood. High blood homocysteine is associated with atherosclerosis (hardening and narrowing of the arteries) and an increased risk for heart problems and, potentially, stroke.

Recycling of HC requires the vitamins folate, B12, and sometimes also B6 and B2. High HC could indicate a deficiency of any of these vitamins. If you decide to take a folate supplement, always look for methylfolate – the body utilizes it much better than synthetic folic acid.

It’s important to have good folate status because it’s required for producing and regulating DNA and other genetic material, for a variety of brain neurotransmitter systems, for the sleep hormone melatonin, for the myelin that electrically insulates nerve cells, and for numerous other essential functions. Many people have a genetic folate mutation that can be better managed using methylfolate.

If you believe you may have a folate problem, ask for a red cell folate test, not a whole blood folate, because it’s far more accurate.

Ferritin Saturation: Indicator of Iron Status

Iron is an essential mineral for us, but it’s so highly reactive it must be kept packaged up, or buffered, by specialized proteins. Ferritin is the most common iron buffer, and the amount of iron per unit ferritin (“saturation”) is a sensitive measure of iron stores.

High ferritin saturation levels are associated with inflammation and other problems. Low levels are associated with anemia, fatigue, and numerous other problems.

Women often have lower iron stores than men, due to blood loss from menstruation, but are healthy if they have normal-range ferritin saturation. Some theorize that this is one of the reasons why women tend to live longer than men.

If your ferritin saturation level is low, consider taking iron. Always be sure that you’re truly iron-deficient before you elect to take an iron supplement – if it escapes control it can be a major risk factor for cardiovascular problems.

Anyone with high ferritin saturation should discuss with their physician whether to donate blood – this would help lower the ferritin saturation level.

Omega-3 Index

Though not respected as blood work basics by many in the medical field, omega-3 fatty acids EPA and DHA are essential for health – they’re practically vitamins. The Omega-3 Index is a measure of the proportion of EPA + DHA in the membranes of your red blood cells, and directly reflects their levels in the brain and other organs.

The Omega-3 Index is a clinically validated biomarker of your overall health, and a low level suggests your brain health may be at risk. Your risk of cognitive decline may significantly rise when your Omega-3 Index is low.

Aim for a level above 8 percent; 4 percent or lower suggests risk for cardiovascular, brain, and other health problems. You can purchase the test here.

Vitamin D

Vitamin D isn’t just a nutrient essential for health – it’s the basis for a hormone that regulates a wide range of important body functions. Low levels of vitamin D have been associated with low mood, cognitive problems, heart and circulatory issues, reduced immunity, and shorter lifespan. The best blood test to get measures the 25-hydroxyvitamin D level.

If you decide to take a vitamin D supplement, make sure it’s vitamin D3, not D2. The D3 form is preferred by the body, and the D2 form may negatively interfere with the benefits of D3.

Thyroid Panel

The thyroid gland is a metabolic “gas pedal” for the body – it regulates our overall metabolic activity, including our body temperature. Abnormal thyroid hormone levels have many negative consequences for health.

Having low thyroid levels, or hypothyroidism, is associated with weight gain and heart problems. Low thyroid symptoms also include fatigue, low mood, mental fog, dry skin, hair loss (especially the outer third of your eyebrows), feeling cold when others feel normal, and constipation.

Overactive thyroid (hyperthyroidism, less common than hypothyroidism) is associated with tiredness, weight loss, feeling too hot and profusely sweating; muscle weakness, rapid heartbeat; eye irritation or discomfort; anxiousness, irritability, and menstrual irregularities.

Here are a few thyroid panels your healthcare professional may order for you if they suspect you have issues with your thyroid:

  • TSH (thyroid-stimulating hormone)
  • Total T3
  • Free T4
  • Thyroid antibodies

Unfortunately, there’s no single test result that will properly diagnose abnormal thyroid function. The key is to get your blood test results and consult with a physician who’s knowledgeable in this area, an endocrinologist if necessary.

Final Thoughts

Keeping up with the blood work basics and other tests we’ve covered is critical to maintaining peak brain and body function. If any of these test results come back outside the healthy range, have them confirmed. Otherwise, your brain and other organs could be at risk for serious health problems.

Work with your physician or other qualified, nutritionally-informed healthcare provider, to determine which of these panels (or others, such as a hormone panel, which may include testosterone, estrogen, and progesterone for men and women) you should get with your next blood draw. They can help you understand the results and how to get them into a healthy a range (if they aren’t already).

Hopefully these blood work basics have given you a deeper knowledge of the various blood tests and why they’re important for you to keep and eye on. Get in the habit of checking your important health numbers on an annual basis, or sooner, as recommended by your physician or healthcare provider.

At BrainMD, we’re dedicated to providing the highest purity nutrients to improve your physical health and overall well-being. For more information about our full list of brain healthy supplements, please visit us at BrainMD.


Keith Rowe
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How is a high SED rate different than high CRP?


I liked this article. I wanted to know the numbers for a healthy range for each test line my blood results will show. What is the range for a healthy woman of 18 to 25, then 26-35, 36 to 45, etc., for each test? I was looking fir something similiar to a bmi chart? Based on your height age and weight your vitamin d levels should be here on the chart. Also, how do I measure cortisol levels and work to decrease them? Thank you!