Environmental conditions
Cold exposure and stay at high altitude may lead to type 1 or type 2 phenotype, depending on duration and other boundary conditions (which determine whether or not stress is associated with energy deprivation). Diagnosis
Affected patients may have normal, low, or slightly elevated TSH depending on the spectrum and phase of illness. Total T4 and T3 levels may be altered by binding protein abnormalities, and medications. Reverse T3 levels are generally increased, while FT3 is decreased. FT4 levels may have a transient increase, before becoming subnormal during severe illness. Correspondingly, in the majority of cases calculated sum activity of peripheral deiodinases (SPINA-GD) is reduced. Generally the levels of free T3 will be lowered, followed by the lowering of free T4 in more severe disease. Several studies described elevated concentrations of 3,5-T2, an active thyroid hormone, in NTIS. 3,5-T2 levels were also observed to correlate with concentrations of rT3 (reverse T3) in patients with euthyroid sick syndrome. NTIS is a component of a complex endocrine adaptation process, so affected patients might also have hyperprolactinemia and elevated levels of corticosteroids (especially cortisol) and growth hormone. NTIS can be difficult to distinguish from other forms of thyroid dysfunction in the hospital setting. Both NTIS and primary hypothyroidism may have reduced fT3 and fT4, and elevated TSH (which is common in the hospital, during the recovery phase of NTIS). Prescribing thyroxine to treat this may lead to lifelong thyroid overtreatment.Hyperthyroidism may be assumed due to decreased TSH and a transient fT4 increase.
Chondrocalcinosis or cartilage calcification is calcification (accumulation of calcium salts) in hyaline cartilage and/or fibrocartilage. It can be seen on radiography. Causes
Buildup of calcium phosphate in the ankle joints has been found in about 50% of the general population, and may be associated with osteoarthritis.Another common cause of chondrocalcinosis is calcium pyrophosphate dihydrate crystal deposition disease (CPPD). CPPD is estimated to affect 4% to 7% of the adult populations of Europe and the United States. Previous studies have overestimated the prevalence by simply estimating the prevalence of chondrocalcinosis regardless of cause.A magnesium deficiency may cause chondrocalcinosis, and magnesium supplementation may reduce or alleviate symptoms. In some cases, arthritis from injury can cause chondrocalcinosis. Other causes of chondrocalcinosis include:
Hypercalcaemia, especially when caused by hyperparathyroidism
Arthritis
Pseudogout
Wilson disease
Hemochromatosis
Ochronosis
Hypophosphatasia
Hypothyroidism
Hyperoxalemia
Acromegaly
Gitelman syndrome

Diagnosis
Chondrocalcinosis can be visualized on projectional radiography, CT scan, MRI, US, and nuclear medicine. CT scans and MRIs show calcific masses (usually within the ligamentum flavum or joint capsule), however radiography is more successful. At ultrasound, chondrocalcinosis may be depicted as echogenic foci with no acoustic shadow within the hyaline cartilage. As with most conditions, chondrocalcinosis can present with similarity to other diseases such as ankylosing spondylitis and gout. == References ==