Occasionally, in people experiencing periodic episodes of paralysis , the potassium level may be drawn during an attack of paralysis. The physical and psychological preparation you can provide for this or any test or procedure depends on your child's age, interests, previous experience, and level of trust. When the needle is inserted to draw blood, some people feel moderate pain, while others feel only a prick or stinging sensation. Afterward, there may be some throbbing . The concentration of potassium inside cells is about 30 times that in the blood and other extracellular fluids.
Aldosterone is secreted from the adrenal gland in the presence of increasing levels of potassium.
For example, in acidosis some of the excess hydrogen ions will shift into cells in exchange for potassium ions being released from the cells. Small changes in the potassium concentration outside cells can have substantial effects on the activity of nerves and muscles. This is particularly true of the heart muscle . Either situation can lead to cardiac arrest in some circumstances. In normal people, taking potassium supplements or potassium-containing drugs is of no consequences, because the kidneys efficiently dispose of excess potassium.