Latest

Learn how HLA-DR and CD38 flow cytometry measures activated T cells, what high results may mean, why ranges vary, and how clinicians plan follow-up.

Activated T-Cell Marker Test: HLA-DR, CD38, Immune Activation, and Inflammation

Understand how CD19 and CD20 B-cell counts are measured, why results may be high or low, how anti-CD20 therapy affects them, and which follow-up tests assess antibody function.

B-Cell Count Test: CD19, CD20, Immune Function, and Antibody Production

Learn what a CD4 count measures, how HIV affects helper T cells, what common ranges and thresholds mean, why results fluctuate, and how the test guides monitoring and infection prevention.

CD4 Count Test: Helper T Cells, Immune Function, HIV Monitoring, and Meaning

Learn how the CD4/CD8 ratio is calculated, what low or high results may mean, why an inverted ratio is nonspecific, and how the test adds context in HIV and immune monitoring.

CD4/CD8 Ratio Test: Immune Balance, High and Low Ratio, and Meaning

Learn what a CD8 count measures, why cytotoxic T-cell numbers may rise or fall, how viral infections affect results, and why cell quantity does not equal antiviral function.

CD8 Count Test: Cytotoxic T Cells, Immune Function, and Viral Response

Understand what a chemokine panel measures, why immune-signaling and cell-migration markers rise or fall, and how specialists interpret patterns and limitations.

Chemokine Panel Test: Immune Signaling, Inflammation, and Cell Migration Markers

Diagnostics

Home Diagnostics Page 9

Understand positive and negative TPOAb results, Hashimoto and Graves associations, normal thyroid function, pregnancy risks, and when follow-up is needed.

Thyroid Peroxidase Antibody (TPOAb) Test: Hashimoto Thyroiditis, Graves Disease, and Results

Understand pregnancy TSH, free T4, TPOAb, and TRAb results, trimester ranges, hypothyroid and hyperthyroid patterns, treatment monitoring, and postpartum care.

Thyroid Tests in Pregnancy: TSH, Free T4, TPOAb, Trimester Ranges, and...

Understand high, low, and normal TSH results, how free T4 and T3 change the meaning, and when repeat testing, treatment review, or urgent care is needed.

Thyroid-Stimulating Hormone (TSH) Test: High, Low, Normal Range, and Thyroid Function...

Understand positive, negative, and borderline TSI results, how TSI differs from TRAb, and how the test guides Graves diagnosis, relapse assessment, and pregnancy care.

Thyroid-Stimulating Immunoglobulin (TSI) Test: Graves Disease, Positive Results, and Meaning

Understand what a TBG blood test measures, why high or low levels alter total T4 and T3, common causes, normal ranges, and the right follow-up tests.

Thyroxine-Binding Globulin (TBG) Test: High, Low, Normal Range, and Thyroid Hormones

Learn how a total T3 blood test detects T3-predominant hyperthyroidism, what high or low results mean, typical ranges, interferences, and follow-up steps.

Total T3 (Triiodothyronine) Test: High, Low, Normal Range, and Hyperthyroidism Results

Understand total T4 testing, including normal ranges, high and low causes, binding-protein effects, pregnancy and newborn use, assay limits, and follow-up.

Total T4 (Thyroxine) Test: High, Low, Normal Range, and Thyroid Function

Learn how TRAb testing confirms Graves disease, how positive or negative results are interpreted, how assays differ, and why TRAb matters in relapse and pregnancy.

TSH Receptor Antibody (TRAb) Test: Graves Disease, Hyperthyroidism, and Results

Understand how TSH with reflex to free T4 works, what abnormal result combinations mean, when the algorithm can miss disease, and which follow-up tests help.

TSH With Reflex to Free T4 Test: Thyroid Screening, Abnormal Results,...

Understand the 17-OHP test, common ranges, CAH and PCOS causes of high results, ACTH stimulation, timing, and the next steps after an abnormal value.

17-Hydroxyprogesterone (17-OHP) Test: Congenital Adrenal Hyperplasia, PCOS, and Results

Learn what an androstenedione blood test shows, why levels may be high or low, how PCOS and adrenal causes differ, and which follow-up tests help.

Androstenedione Blood Test: High, Low, PCOS, Adrenal, and Fertility Results

Understand AMH testing for ovarian reserve, fertility treatment response, high and low results, PCOS, age effects, limitations, and useful next steps.

Anti-Mullerian Hormone (AMH) Test: Ovarian Reserve, Fertility, and Results

Understand bioavailable testosterone, how SHBG and albumin affect results, causes of high or low levels, testing methods, and safe follow-up steps.

Bioavailable Testosterone Test: High, Low, Normal Range, and Results

Learn when to schedule a day 21 progesterone test, what levels can confirm ovulation, why low results occur, and why one value cannot grade luteal quality.

Day 21 Progesterone Test: Ovulation Confirmation, Luteal Phase, Normal Range, and...

Understand the DHEA-S test, age-specific ranges, adrenal causes of high or low results, links with PCOS and CAH, and the follow-up tests that help.

Dehydroepiandrosterone Sulfate (DHEA-S) Test: High, Low, Normal Range, and Results

Understand delayed puberty hormone testing with LH, FSH, estradiol, and testosterone, common result patterns, age cutoffs, causes, and next steps.

Delayed Puberty Hormone Test Panel: LH, FSH, Estradiol, Testosterone, and Results

Understand estradiol testing, cycle and menopause ranges, causes of high or low E2, fertility uses, related hormone patterns, and next steps after results.

Estradiol (E2) Test: High, Low, Normal Range, Fertility, and Menopause Results

Understand estriol testing in pregnancy, how uE3 and MoM support prenatal screening, causes of low results, and follow-up options after an abnormal screen.

Estriol (E3) Test: Pregnancy, Placenta Health, and Results

Learn how estradiol, estrone, and estriol tests differ, what high or low estrogen results may mean, how life stage affects ranges, and which follow-up helps.

Estrogen Levels Test: Estradiol, Estrone, Estriol, High and Low Results, and...

Understand estrone testing in menopause and other settings, why E1 may be high or low, how it differs from estradiol, and what follow-up is useful.

Estrone (E1) Test: Menopause, Estrogen Levels, High and Low Results

1...8910...74 Page 9 of 74