Hi I'm a 21 year old male my height is 6'1 and my calcium levels over last three months checked at an interval of 10-15 days have been: 10.5, 10.4, 10.0, 9.6 mg/dl.. I'm worried I might have hyperparathyroidism. My calcium levels hover between 9.6 and 10.5 whenever checked.
I understand your concerns. Calcium levels of 10.5 or 10.4 mg/dl is considered high for older adults, and so your lab may flag it as high on your results. At your age, though, it is normal to have calcium levels in the mid 10s. Most labs will adjust calcium ranges for children and won’t bother adjusting with adults - but even adults in their 30s can still have calcium levels in the low 10s. Eventually, typically by age 40, the levels will tend to drop into the 9s.
With your current levels, it is unlikely that you have primary hyperparathyroidism. To confirm, you could check a set of labs to include the calcium and PTH level together.
If your calcium levels start to run into the high 10s, or you have a high PTH level, then I would be more concerned about primary hyperparathyroidism.