11 yr. old - dramatic weight fluctuation

You may want to schedule an appointment with her doctor. Has she had any other signs of diabeties like:

Frequent urination
Excessive thirst
Extreme hunger
Unusual weight loss or gain
Increased or overwhelming fatigue
Constant Irritability
Blurry vision unstable sight

These all can be signs of diabetes, but it also could have to do with instable hormonal changes.

Good luck!

I would also suggest having her thyroid checked because some of the symptoms you listed are the same as mine and i didn't know what was causing it and the doctor had my thyroid level checked and surely enough that is what the problem was.

As a doctor, I would suspect Thyroiditis. Silent thyroiditis, also known as painless thyroiditis or more specifically and scientifically as subacute lymphocytic thyroiditis, is a member of the group of thyroiditis conditions known as resolving thyroiditis.

Silent thyroiditis features a small goiter without tenderness and, like the other types of resolving thyroiditis, tends to have a phase of hyperthyroidism followed by a phase of hypothyroidism then a return to euthyroidism (normal thyroid function). The time span of each phase is not concrete, but the hypo phase usually lasts 2-3 months.

The symptoms are those of hyperthyroidism and hypothyroidism during these phases. During the hyperthyroidism phase, RAIU (Radioactive Iodine Uptake) is suppressed while during the hypothyroidism phase it is increased. Thyroid autoantibodies (anti-thyroglobulin, anti-thyroid peroxidase) may be present, but the extent of their role in silent thyroiditis is unknown.

Silent thyroiditis is most likely autoimmune. Hashimoto's thyroiditis is also known as chronic lymphocytic thyroiditis and is, therefore, in the same "family" as silent thyroiditis.

While this is harder to diagnose then other thyroid conditions because it fluctates back and forth from hyper to hypo, and causes little symptoms, it is worth looking into.