These signs can be considered "occult," as no one symptom may be severe enough to seek medical attention, leaving the triad to go unnoticed or untreated. Disordered eating
Energy availability is defined as energy intake minus energy expended. Energy is taken in through food consumption. Bodies expend energy through normal functioning as well as through exercise. In the case of RED-S, low energy availability may be due to eating disorders, but not necessarily so. Athletes may experience low energy availability by exercising more without a concomitant change in eating habits, or they may increase their energy expenditure while also eating less. Disordered eating is defined among this situation due to the low caloric intake or low energy availability. While most athletes do not meet the clinical criteria to be diagnosed with an eating disorder such as anorexia nervosa or bulimia nervosa, many will exhibit disordered eating habits such as fasting, as well as avoiding certain types of food the athlete thinks are "bad" (such as foods containing fat). There are multiple factors that play in encouraging athletes to aim for a more lean body type, such as the culture and the individual. More severe examples of disordered eating habits may include binge-eating; purging; and the use of diet-pills, laxatives, diuretics, and enemas.By restricting their diet, the athlete may worsen their problem of low energy availability.
Balkan endemic nephropathy (BEN) is a form of interstitial nephritis causing kidney failure. It was first identified in the 1920s among several small, discrete communities along the Danube River and its major tributaries, in the modern countries of Croatia, Bosnia and Herzegovina, Serbia, Romania, and Bulgaria. It is caused by small long-term doses of aristolochic acid in the diet. The disease primarily affects people 30 to 60 years of age. Doses of the toxin are usually low and people moving to endemic areas typically develop the condition only when they have lived there for 10–20 years. People taking higher doses of aristolochic acid (as Chinese herbal supplements) have developed kidney failure after shorter durations of exposure. Signs and symptoms
The patients are distinguished from those suffering from other causes of end-stage renal disease by showing an absence of high blood pressure, xanthochromia of palms and soles (Tanchevs sign), early hypochromic anemia, absence of proteinuria, and slow progression of kidney failure. There is no specific therapy; BEN causes end-stage renal disease, for which the only effective treatments are dialysis or a kidney transplant. In endemic areas BEN is responsible for up to 70% of end-stage renal disease. At least 25,000 individuals are known to have this form of the disease.Patients with BEN have a greatly increased rate of transitional cell carcinoma of the upper urothelial tract, (the renal pelvis and ureters). (In populations without BEN, most urothelial cancer occurs in the bladder. )