04 November 2025
: Case report 
Post-COVID-19 Painless Thyroiditis: A Case Study on Thyrotoxicosis Management
Challenging differential diagnosis, Rare disease
Siddharth Patel
ABCDEF 1*, William R. Norman EF 2, Prutha Pathak BDE 3, Laurence Stolzenberg BD 4, Alexis Koch BF 2, Raphael Quansah E 1, Mrudula Thiriveedi EF 1, Mc Anto Antony DE 5, Rajdeep Singh EF 6, Sujatha Baddam EF 7
DOI: 10.12659/AJCR.948356
Am J Case Rep 2025; 26:e948356
Table 1 Laboratory findings and diagnostic results.
| Lab Test | Result | Reference range |
|---|---|---|
| White blood cell count | 10.60×1000 cells/microL | 4.8–10.8×1000 cells/microL |
| Hemoglobin | 9.6 g/dL | 13.5–17.5 g/dL |
| Platelet count | 315×1000 cells/microL | 130–400×1000 cells/microL |
| Sodium | 135 mmol/L | 135–145 mmol/L |
| Blood urea nitrogen (BUN) | 37 mg/dL | 7–20 mg/dL |
| Creatinine | 1.2 mg/dL | 0.6–1.2 mg/dL |
| Potassium | 6.2 mEq/L | 3.5–5.0 mEq/L |
| Calcium | 9.6 mg/dL | 8.8–10.2 mg/dL |
| Phosphorus | 5.5 mg/dL | 2.6–5.5 mg/dL |
| AST | 22 U/L | 10–34 U/L |
| ALT | 35 U/L | 10–44 U/L |
| Alkaline phosphatase | 96 U/L | 32–122 U/L |
| Erythrocyte sedimentation rate | 27 mm/h | 0–15 mm/hr |
| C-reactive protein | 11.7 mg/L | 0–5 mg/L |
| Thyroid-stimulating hormone (TSH) | 0.01 mIU/L | 0.4–4.0 mIU/L |
| Free T4 | >7.7 ng/dL | 0.93–1.70 ng/dL |
| Free T3 | 10.9 pg/mL | 2.6–4.4 pg/mL |
| Thyroid-stimulating immunoglobulins | Negative | Negative |
| Anti-thyroid peroxidase antibodies | Negative | Negative |
| SARS-CoV-2 spike antibody IgG | 441 U/mL | <0.80 u/mL |