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Is Your Doctor Ordering These 7 Important Tests?

Written by Biljana Novkovic, PhD | Last updated:
Puya Yazdi
Medically reviewed by
Puya Yazdi, MD | Written by Biljana Novkovic, PhD | Last updated:

Are you regularly doing your CBCs and CMPs and checking your cholesterol levels? That’s great. And if you are feeling well and overall healthy, it’s likely enough. But what happens when all of these tests are coming back normal yet you still feel like something is wrong? It may be time to dig deeper. Here are some of the tests you and your doctor can easily incorporate into your regular check-ups that can tell you a lot more about your body and help reveal important issues and imbalances.

What Blood Tests Should You Get?

We now have at our disposal more ways to tell what’s going on in our bodies than ever before. But oftentimes, these tests are not relied upon, especially when it comes to prevention.

For example, you may be testing your glucose, but not your insulin levels. You may be checking your iron, but not your ferritin. Your lab results may suggest everything is fine until things get seriously out of order. But the truth is – your body may be functioning suboptimally, and, with the right tests, your doctor can often tell.

Here are eight tests that are great to catch chronic diseases in their early stages. Discuss taking them with your doctor. One of these may just be a game-changer for you.

Important Tests You May Not Be Getting

1) Insulin

Even if your blood sugar (glucose) levels are fine, your body may still be struggling to keep them in line. You will know if that’s the case when you check your insulin levels.

Insulin is a hormone that is released when you eat in order to help move glucose from the blood into the tissues (mainly muscles, fat tissue, and liver) [1, 2]. Insulin levels can go out of balance long before blood sugar does (you can read more about insulin resistance here).

Researchers found that having fasting insulin levels above the optimal range increases your risk of developing metabolic syndrome, diabetes, heart disease, and dementia [3, 4, 5, 6, 7, 8]. For example, one study found that a fasting insulin level above 9.0 uIU/mL (well within the normal range of up to 25 uIU/mL) could identify prediabetes with 80% accuracy [5].

2) Ferritin

You may be testing your iron levels, but are you checking your ferritin? Even if your iron is within the normal range, low ferritin can indicate iron deficiency. And if you have unexplained fatigue and ferritin is on the lower side – that indicates you are deficient in iron.

Ferritin is an iron-storing protein. It is important for maintaining proper levels of iron and making sure that iron is available for the different bodily processes that need it. Essentially, ferritin is a measure of your body’s iron stores [9].

Low ferritin levels are usually due to some kind of gut inflammation that is not allowing the person to absorb iron well, or because of hypothyroidism. When iron (indicated by ferritin) is lower, it can worsen existing health problems. Studies suggest that low ferritin may increase the risk of depression and anxiety by about twofold [10, 11].

Conversely, ferritin may be high in many chronic inflammatory conditions including metabolic syndrome, fatty liver, kidney disease, autoimmune disease, diabetes, and cancer [12]. This makes ferritin a marker of acute and chronic inflammation.

You can read more about ferritin here.

3) Magnesium

Here is an alarming statistic – research suggests that about half (48%) of the U.S. population is deficient in magnesium [13].

Why is this alarming? Magnesium is the 4th most abundant mineral in our bodies and it’s required for more than 300 different bodily processes [14, 15]. A deficiency can wreak havoc on your health. When your magnesium levels are low, you may experience a loss of appetite, fatigue, nausea, insomnia, irritability, and muscle weakness.

In addition, the older you get, the less efficiently your body holds onto magnesium [16, 17, 18]. In its worst stages, magnesium deficiency can contribute to osteoporosis, heart disease, high blood pressure, and diabetes [19, 20, 21, 22, 15, 14, 23].

Thankfully, magnesium levels are very easy to test. If your levels are suboptimal or low, you can correct them by increasing your intake of magnesium-rich foods or supplementing.

4) hs-CRP

Another important marker to keep track of if you are concerned about your heart health is C-reactive protein (CRP). Doctors use it to help predict your risk of heart disease. One study suggests that when both CRP and cholesterol levels are high, it may increase the overall risk of heart disease up to ninefold [24]!

CRP is a protein that increases in response to chronic stress (lack of sleep, emotional issues, smoking, alcoholism, diabetes, nutritional deficiencies, etc.). It’s a great measure of chronic inflammation in your body.

5) LDL Particle Number and Size

Concerned about heart disease? You may be checking your cholesterol levels regularly (if you are not, you should be). But what about your LDL particle number?

LDL particles transport cholesterol in the bloodstream. You can think of LDL particles as cars on a highway (blood vessel) and cholesterol and fats like triglycerides as the passengers. A standard lipid panel will give you a measure of the number of passengers on the roads, but you need LDL particle number to know the number of cars. In addition, LDL particles come in different sizes, with large particles able to carry more cholesterol (buses and SUVs) than small particles (2-seaters) [25].

Why do LDL particle number and size matter?

For decades, reducing LDL cholesterol has been the primary target for doctors in treating and preventing heart disease. However, researchers found that almost 50% of people who have a heart attack have normal LDL cholesterol levels! In addition, in clinical trials with LDL cholesterol-reducing drugs (statins), a substantial number of patients taking these drugs continue to have heart attacks and strokes [26, 27, 28].

This has led researchers to look for other measures, such as LDL particle size, that could better predict heart disease risk and serve as a better treatment target than LDL cholesterol.

That’s because, while small LDL particles carry less cholesterol than the larger particles, they are linked with a greater risk of hardening of the arteries (atherosclerosis) and heart disease than large LDL particles, and even LDL cholesterol [29, 30, 31, 32, 33, 34, 35].

Work with your doctor to find out if testing LDL particles makes sense in your particular case.

6) Testosterone (Free or Bioavailable)

Testosterone levels decline as we age, and men and women alike are affected. This hormone protects men from obesity, depression, osteoporosis, and heart disease. Similarly, low levels have been linked with decreased libido and well-being in women [36, 37, 38].

Now, you may have been testing just your total testosterone. But total testosterone doesn’t tell the whole story. This is because it’s only the unbound (bioavailable) testosterone that works its magic in your body. Both free and total testosterone levels peak in the late 20s and decline from then on in both men and women. However, SHBG (sex hormone binding globulin), a protein that binds testosterone making it inactive, increases with age. This means that free testosterone levels will decline more dramatically with age than total testosterone levels [39, 40].

Free testosterone levels are less often measured than total testosterone because it’s a more expensive and difficult test to perform. However, if you have symptoms of low testosterone (weakness, fatigue, depression, irritability, low libido, decreased muscle mass, insomnia, bones that decrease in density) but have normal total testosterone levels, it’s definitely a test worth getting [41].

7) Estradiol

Estradiol is important for female and male fertility, brain and thyroid function, bone health, and maintaining a healthy weight.

Studies suggest that people with low estradiol levels can have an impaired stress response and may be more susceptible to stress [42]. Low levels increase the risk of osteoporosis and bone fractures in men and women alike [43, 44]. In addition, there is evidence that shows low estrogen increases the risk of developing heart disease and metabolic syndrome [45, 46].

For women, estradiol levels decrease sharply during menopause. This decrease contributes to age-related declines in memory and learning [47]. In addition, one study showed that post-menopausal women with lower estrogen levels tended to gain weight, but those who had hormone therapy did not [48].

On the other hand, high estrogen levels can decrease sex drive in men. They also may increase the risk of stroke and cancer (especially breast cancer in women) [49, 50].

Hormones control a lot of different functions in our bodies, but we often don’t test them until things become serious. It may be a good idea to check your hormone levels once in a while to make sure everything is in order.

About the Author

Biljana Novkovic

Biljana Novkovic

Biljana received her PhD from Hokkaido University.
Before joining SelfHacked, she was a research scientist with extensive field and laboratory experience. She spent 4 years reviewing the scientific literature on supplements, lab tests and other areas of health sciences. She is passionate about releasing the most accurate science and health information available on topics, and she's meticulous when writing and reviewing articles to make sure the science is sound. She believes that SelfHacked has the best science that is also layperson-friendly on the web.


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