Potassium plays integral roles in fluid balance, muscle contraction, nervous system function, blood pressure, heart health and bone health. In addition to being characterized as a mineral, potassium is also an electrolyte. Electrolytes are minerals that carry either a positive or negative charge. They maintain fluid balance and keep the pH of the blood normal, which ensures that the acid-base balance in the body is maintained. An eating disorder can lead to dangerously low levels of potassium.
Normal potassium levels are defined as 3.6 to 4.8 mEq/L of blood. Low potassium levels are defined as anything under 3.6 mEq/L. A dangerously low potassium level is defined by MayoClinic.com as less than 2.5 mEq/L.
The eating disorder that results in low potassium levels is bulimia nervosa, which is characterized by episodes of binge-eating followed by purging, either through self-induced vomiting or the excessive use of laxatives. Electrolytes are lost through chronic vomiting and diarrhea. To prevent electrolyte imbalances, such as low potassium, these lost electrolytes must be replenished, either through oral ingestion of electrolyte solutions or intravenous administration. Those with bulimia nervosa constantly vomit or defecate several times throughout the day. Because of this, lost potassium is not replaced and low potassium blood levels can develop.
Mild decreases in potassium levels do not usually cause any symptoms. As the condition progresses, however, it can become life-threatening. Low potassium levels in the blood can cause abnormal heart rhythms, or arrhythmias; the breakdown of muscle fibers; constipation; fatigue; muscle weakness; muscle spasms; and paralysis.
Treating low potassium levels in someone who is bulimic is often difficult because usual treatment involves oral supplementation of potassium. Because bulimics are constantly purging, any ingested potassium would quickly be expelled from the body. Bulimics with severely low potassium levels are often hospitalized so that they can be monitored, while also given intravenous or oral supplementation of potassium. Therapy may also be part of the treatment plan for a bulimic with a low potassium level.
If left untreated, low potassium levels can cause dangerous irregularities in heartbeat as well as lung paralysis, which makes it impossible to breathe, according to Medline Plus. Chronic low potassium levels can also lead to a specific type of kidney damage known as hypokalemic neuropathy.