These 5 Blood Tests Can Save Your Life!
Why Not Test Everything?
Before we get to the recommended tests, let me briefly explain why doctors don't routinely test "everything." This isn't a question of cost or convenience, but has a solid scientific foundation.
Every test – including blood tests – has a certain degree of inaccuracy. They can produce both falsely high and falsely low values, leading to false positive and false negative results. In medicine, we refer to this as sensitivity (how well a test identifies those with the disease) and specificity (how well a test identifies those without the disease).
Let's consider an example: For a condition that occurs in only one out of 1,000 patients, we use a test with a false-positive rate of 10 per 1,000. What would happen? Out of 1,000 tested individuals, 10 would receive a positive result, although statistically only one person would actually be affected. This means: 9 out of 10 positive results would be false!
This not only leads to unnecessary anxiety but potentially also to further, possibly stressful examinations or even treatments that weren't necessary in the first place.
The Positive Predictive Value as a Solution
Fortunately, there's a solution: the positive predictive value. Through a targeted selection process, doctors try to test only those individuals for whom the probability of a particular disease is increased.
Taking our previous example: If we only test people whom we suspect of having the condition based on symptoms, family history, or other factors with a 50% certainty, the ratio changes dramatically. Among 1,000 such selected patients, we would still have 10 false-positive results, but now also 500 true-positive ones! The ratio of 500:10 suddenly makes the test very valuable.
This explains why your doctor doesn't immediately order "all" tests, but makes a careful selection based on your individual situation.
The 5 Most Important Blood Tests for Everyone
Now for the tests that, in my experience, are important for virtually every person:
1. Lipoprotein(a) – Lp(a)
This value is almost exclusively genetically determined and shows your individual risk for heart and vascular diseases. High Lp(a) levels can lead to atherosclerosis independent of other risk factors, potentially causing heart attacks or strokes.
Everyone should have this value determined once in their lifetime. If it's elevated, it's particularly important to pay careful attention to other risk factors and consistently minimize them.
2. Comprehensive Lipid Analysis
This includes LDL cholesterol (the "bad" cholesterol), HDL cholesterol (the "good" cholesterol), total cholesterol, and triglycerides. In some cases, determining ApoB is also useful.
Why ApoB is Better Than LDL
ApoB (Apolipoprotein B) is actually a more precise risk marker for cardiovascular diseases than conventional LDL cholesterol. Why is that?
Imagine blood lipids as small transport vehicles in the bloodstream. Each of these vehicles (lipoproteins) can transport different amounts of cholesterol. The problem: With standard LDL measurement, only the total "cargo" is measured, not the number of "vehicles."
ApoB, on the other hand, shows exactly how many of these potentially dangerous particles are actually circulating in your blood. Since each of these particles contains exactly one ApoB molecule, the ApoB value gives the exact number. And this number is more crucial for your risk than the total amount of transported cholesterol.
Especially in people with diabetes, insulin resistance, or metabolic syndrome, the LDL value may appear normal despite the presence of many small, particularly dangerous LDL particles – a risk that can only be identified through ApoB.
While ApoB testing is more expensive than standard lipid panels, for people with a family history of cardiovascular disease or other risk factors, this investment can certainly be worthwhile.
3. HbA1c – The Long-term Blood Sugar Value
The HbA1c value provides information about your average blood sugar level over the past 2-3 months. It's important not just for diabetics but for everyone, as it can provide early indications of developing insulin resistance or incipient diabetes.
An elevated HbA1c value can be a warning sign long before other symptoms appear – and gives you the chance to counteract through lifestyle changes.
4. Kidney Function
The determination of potassium (K), sodium (Na), and creatinine (or cystatin C) provides information about your kidney function.
Creatinine vs. Cystatin C: Which is Better?
The classic kidney function marker is creatinine – a breakdown product from muscle metabolism. However, there are two important limitations that not everyone is aware of:
Influence of muscle mass: People with a lot of muscle mass naturally have higher creatinine values. A well-trained athlete can therefore have "elevated" values without their kidneys being impaired. Conversely, elderly people or individuals with low muscle mass can have normal values despite their kidney function already being limited.
Influence of creatine supplements: Particularly interesting for athletes: Taking creatine – a popular dietary supplement in strength training – can artificially increase creatinine levels. This is because creatine is broken down into creatinine in the body. According to current studies, the increase in creatinine levels due to creatine supplementation can be between 15% and 30%, without any kidney dysfunction being present.
Cystatin C offers a decisive advantage here: It is produced in almost all nucleated cells in a constant amount and is independent of muscle mass. Nutritional supplements like creatine also have no influence on this value. Cystatin C is therefore the more reliable marker, especially for athletes, elderly people, or individuals with significantly deviating muscle mass.
While cystatin C testing is generally more expensive than standard creatinine testing, it provides a more accurate assessment for certain populations.
5. Complete Blood Count
The complete blood count is like an all-around look at your general health status. It includes:
- The basic blood count: Shows the number and properties of red blood cells (important for oxygen transport), platelets (important for blood clotting), and white blood cells (important for immune defense).
- The differential blood count: A detailed breakdown of the different types of white blood cells.
This examination can provide indications of anemia, infections, inflammations, autoimmune diseases, and even certain types of cancer.
Additional Tests for Specific Groups
Depending on individual situations, further tests may be useful:
Liver Function (Bilirubin, ALT, AST, Amylase)
Particularly important for known liver diseases, regular medication intake, or increased alcohol consumption.
Thyroid Function (TSH and possibly T3 + T4)
Useful for unclear symptoms such as chronic fatigue, weight changes, or mood swings, especially in women over 50.
Micronutrients (Vitamin D, Vitamin B12, etc.)
Relevant for special diets (e.g., vegan/vegetarian), chronic gastrointestinal diseases, or specific symptoms.
Cancer Markers
For screening, the PSA test is suitable for men of a certain age for early detection of prostate cancer – however, you should weigh the advantages and disadvantages together with your doctor.
Conclusion
These five basic blood tests form a solid foundation for your preventive healthcare. They can detect risk factors early and give you the opportunity to counteract in time – before serious diseases develop.
Particularly, the differentiated consideration of ApoB instead of conventional LDL and cystatin C instead of creatinine can give you a more precise insight into your actual health status. This is especially relevant if you are an athlete, take dietary supplements, or have other factors that could distort standard values.
Remember: These tests do not replace visiting a doctor and their expert advice. They are rather a valuable tool that you can use together with your doctor to protect your health in the long term.
Invest in your health – because it's your most valuable asset!
