Do steroids affect blood levels? A comprehensive look at the impact on blood test results

October 13, 2025 •

5 min read

According to a 2025 study from Cleveland Clinic researchers, white blood cell counts can increase by up to 4,840 cells/mm$^3$ within 48 hours of starting high-dose corticosteroids, demonstrating a clear and measurable change in blood composition. This illustrates a fundamental answer to the question, 'Do steroids affect blood levels?': Yes, they can significantly and measurably alter various parameters found in blood tests.

Quick Summary

Steroids profoundly impact multiple components of blood tests, including glucose, electrolytes, lipids, and blood cell counts. The specific effects depend on the type of steroid (corticosteroid vs. anabolic) and duration of use. Corticosteroids can induce hyperglycemia, alter electrolytes, and increase white blood cell counts. Anabolic steroids cause dramatic changes to cholesterol levels and can elevate liver enzymes.

Key Points

Corticosteroids Cause Hyperglycemia: Steroids like prednisone can significantly increase blood sugar levels by causing insulin resistance and promoting liver glucose production, a risk factor for steroid-induced diabetes.
Anabolic Steroids Damage Cholesterol: Anabolic steroid use drastically lowers 'good' HDL cholesterol and raises 'bad' LDL cholesterol, increasing the risk of cardiovascular disease.
Blood Cell Counts Change with Corticosteroids: Corticosteroids cause a rise in white blood cell counts, primarily neutrophils, while decreasing lymphocytes and eosinophils.
Electrolyte Levels Fluctuate with Corticosteroids: High-dose or long-term corticosteroid therapy can cause hypernatremia, hypokalemia, and increase calcium excretion, leading to fluid retention.
Anabolic Steroids Raise Liver Enzymes: Use of anabolic steroids often leads to elevated liver enzymes (ALT and AST), indicating potential liver damage or stress.
Steroids Suppress Natural Hormones: Both corticosteroids and anabolic steroids interfere with the body's natural hormone production, with AAS suppressing testosterone, LH, and FSH, and corticosteroids affecting the HPA axis.
Monitoring is Crucial: Due to these significant effects, regular blood monitoring is essential for managing health risks associated with steroid use, especially for long-term or high-dose regimens.

A Tale of Two Steroids: Distinguishing Corticosteroids from Anabolic Steroids

When addressing the question, "Do steroids affect blood levels?", it is crucial to understand that the term "steroid" encompasses two distinct classes of drugs with different effects on the body. The effects on blood tests vary considerably between these two groups.

Corticosteroids: These medications, like prednisone and dexamethasone, are primarily used to reduce inflammation and suppress the immune system in conditions such as asthma, arthritis, and autoimmune diseases. Their effects on blood work are tied to their influence on metabolism and mineral balance.
Anabolic-Androgenic Steroids (AAS): These are synthetic versions of the male hormone testosterone, often misused by athletes and bodybuilders to increase muscle mass and enhance performance. Their impact on blood test results is related to their hormonal effects on lipid metabolism and organ function.

The Effect of Corticosteroids on Blood Levels

Blood Glucose and Steroid-Induced Hyperglycemia

One of the most well-known side effects of corticosteroids is their impact on blood sugar levels. Corticosteroids raise blood glucose through several mechanisms:

Increased Gluconeogenesis: They stimulate the liver to produce and release more stored glucose into the bloodstream.
Reduced Insulin Sensitivity: They can cause insulin resistance, meaning the body's cells don't respond effectively to insulin, leading to sugar accumulating in the blood.
Pancreatic Beta Cell Changes: They can alter the function of pancreatic beta cells, which are responsible for insulin production.

This can lead to a condition known as steroid-induced hyperglycemia. In some cases, prolonged use can result in steroid-induced diabetes, even in individuals without a prior history of diabetes. The degree of hyperglycemia depends on factors such as the steroid dose, type, and the time of day it is taken. High-risk individuals include those with prediabetes, a family history of diabetes, or a higher body mass index. For patients with pre-existing diabetes, this effect necessitates close blood sugar monitoring and potential adjustments to their treatment plan.

Electrolyte and Mineral Imbalances

Corticosteroids, especially at high doses or with prolonged use, can disrupt the body's electrolyte balance.

Sodium and Potassium: Certain corticosteroids, particularly those with mineralocorticoid activity like cortisone and fludrocortisone, can cause the body to retain sodium while excreting potassium. This can lead to hypernatremia (high sodium), hypokalemia (low potassium), and fluid retention, which may elevate blood pressure.
Calcium: All corticosteroids are known to increase calcium excretion, interfering with its absorption. Over time, this can lead to low blood calcium (hypocalcemia) and is a contributing factor to osteoporosis with long-term steroid therapy.

Changes in Complete Blood Count (CBC)

Steroids can alter the composition of your blood cells, an effect known as leukocytosis.

White Blood Cells (WBCs): Corticosteroid use typically causes a significant rise in the total white blood cell count, primarily due to an increase in neutrophils. The effect is dose-dependent, peaking around 48 hours after a high dose. This can complicate the diagnosis of infection, as a high WBC count is a common indicator.
Other Blood Cells: In contrast to neutrophils, corticosteroids can cause a decrease in other white blood cells, including lymphocytes, monocytes, and eosinophils. They can also cause a slight increase in red blood cell content.

The Effect of Anabolic Steroids on Blood Levels

Lipid Profile Abnormalities

Misuse of anabolic-androgenic steroids has a well-documented and severe negative impact on cardiovascular health, largely mediated by changes in blood lipids.

HDL and LDL Cholesterol: AAS use causes a dramatic decrease in "good" high-density lipoprotein (HDL) cholesterol and a significant increase in "bad" low-density lipoprotein (LDL) cholesterol. A case study showed a 90% reduction in HDL and a 100% increase in LDL over a five-year period of cyclical use. This atherogenic profile significantly raises the risk of cardiovascular events, such as heart attack and stroke.

Liver Function

The liver is responsible for metabolizing anabolic steroids, and chronic use can result in hepatotoxicity. Blood tests for liver function will often show elevated levels of liver enzymes, such as alanine transaminase (ALT) and aspartate transaminase (AST), indicating liver stress or damage.

Hormone Levels

Exogenous testosterone from AAS suppresses the body's natural hormone production through a negative feedback loop. Blood tests will typically reveal:

Suppressed Natural Hormones: Abnormally low levels of hormones produced by the pituitary gland, such as luteinizing hormone (LH) and follicle-stimulating hormone (FSH).
Altered Androgens and Estrogens: Elevated total testosterone levels, which can also lead to changes in estradiol due to aromatization.

Comparison of Blood Level Effects: Corticosteroids vs. Anabolic Steroids


Blood Parameter	Corticosteroids (e.g., Prednisone)	Anabolic Steroids (e.g., Testosterone)
Blood Glucose	Significantly increased (hyperglycemia) via insulin resistance and increased liver glucose output. Can cause steroid-induced diabetes.	Can increase fasting insulin and may impair glucose tolerance, contributing to metabolic syndrome.
Cholesterol (Lipids)	Can cause dyslipidemia, though typically less severe than AAS.	Causes a dramatic decrease in HDL and a significant increase in LDL, severely worsening cardiovascular risk.
White Blood Cells	Causes leukocytosis (increase in total WBCs), primarily neutrophils, but decreases lymphocytes and eosinophils.	Can cause polycythemia (increase in red blood cells), but effects on WBCs are less prominent.
Electrolytes	Can cause hypernatremia, hypokalemia, and increased calcium excretion, leading to fluid retention.	Less direct effect on electrolytes, but fluid retention can occur through different mechanisms.
Liver Enzymes	Possible elevation, but less pronounced than with AAS.	Significant and frequent elevation of ALT and AST, indicating hepatotoxicity.
Hormone Profile	Suppresses the hypothalamic-pituitary-adrenal (HPA) axis, affecting the body's natural cortisol production.	Suppresses natural testosterone, LH, and FSH production.

The Critical Importance of Blood Monitoring

Given the wide-ranging and significant effects that steroids have on blood composition, regular and targeted blood monitoring is crucial for anyone taking these medications.

For those on corticosteroids, monitoring should focus on blood glucose, especially for those with or at risk of diabetes. Electrolyte levels, particularly potassium and sodium, should also be checked to manage fluid balance and blood pressure. A complete blood count (CBC) helps interpret any unexpected signs of infection in the context of steroid-induced leukocytosis.

For individuals using anabolic steroids, blood monitoring is vital for detecting liver stress (via liver function tests) and managing cardiovascular risk (by checking the lipid panel). Monitoring hormone levels is also necessary to assess the degree of natural production suppression. It is recommended that individuals on AAS get blood work done every 8-12 weeks, even if asymptomatic.

Conclusion: Understanding and Managing the Impact

In summary, steroids undeniably affect blood levels, but the specific changes depend heavily on the type of steroid being used. Corticosteroids primarily influence glucose, electrolytes, and white blood cell counts, while anabolic steroids dramatically alter lipid profiles and suppress natural hormone production. For both medical patients and those misusing performance-enhancing drugs, these alterations carry significant health implications, emphasizing the importance of vigilant monitoring. Understanding how different steroids affect blood composition is the first step toward mitigating potential risks and making informed health decisions.

For more information on the impact of corticosteroids, consider visiting the National Institutes of Health (NIH) for comprehensive medical resources.

Frequently Asked Questions

Corticosteroids can affect several blood tests, including blood glucose levels, a complete blood count (CBC) showing an increase in white blood cells (leukocytosis), and electrolyte panels, which may indicate altered sodium and potassium levels.

Yes, corticosteroids can induce a temporary type of diabetes known as steroid-induced diabetes or steroid hyperglycemia. This often resolves after the medication is stopped, but in some individuals, particularly those with pre-existing risk factors, it can become permanent.

The duration of steroid effects on blood work varies. For oral corticosteroids, blood sugar can rise within days, while steroid injections may cause elevated blood sugar for 3 to 10 days. Anabolic steroid effects on lipids may take several months to normalize after cessation.

Anabolic steroids alter lipid metabolism by dramatically decreasing 'good' HDL cholesterol and increasing 'bad' LDL cholesterol. This is thought to be partly due to increased activity of the enzyme hepatic triglyceride lipase.

Yes, a high white blood cell count (leukocytosis) is a common and expected side effect of corticosteroid use. The increase is typically dose-dependent and peaks around 48 hours after administration, and does not necessarily indicate an infection.

For long-term corticosteroid therapy, regular monitoring should include blood glucose, blood pressure, electrolyte levels (sodium, potassium, calcium), and bone density scans due to the increased risk of osteoporosis.

Doctors need to know about recent steroid use because it can suppress the adrenal glands, potentially leading to adrenal insufficiency during physical stress like surgery. Supplementing with 'stress steroids' may be necessary to prevent a life-threatening drop in blood pressure.