The Cleveland Clinic defines a tremor as a rhythmic, involuntary, oscillating movement of a body part that occurs in isolation or as part of a clinical syndrome. There are several types of tremors, and many diseases and conditions can cause them. If you experience a tremor in the absence of a known disease, your doctor can perform laboratory tests to determine the presence of a systemic problem such as hyperthyroidism -- a condition of high levels of thyroid hormone -- or electrolyte imbalance.
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The human body requires specific vitamins and minerals to function. Doctors refer to these nutrients as essential nutrients since they are required for life. Several of the essential minerals, including sodium, potassium, calcium, magnesium and phosphorus, function as electrolytes because they carry an electrical charge. Electrolytes help balance the level of fluid inside and outside of cells and transmit electrical impulses between nerves and cells. This makes electrolytes important for a healthy nervous system. An electrolyte imbalance can interfere with the electrical impulses sent between nerves and muscle cells and cause a tremor.
Your body uses the majority, approximately 99 percent, of the calcium to build strong bones and teeth. The remaining 1 percent that stays in the blood and soft tissues plays a vital role in muscle contraction. A specialized structure within muscle cells, known as the sarcoplasmic reticulum, stores calcium ions. When nerves send electrical impulses to that cell, calcium flows out of the sarcoplasmic reticulum into the fluid portion of the cell. This movement triggers the muscle cells to contract. A low blood calcium level, known as hypocalcemia, causes tremorlike symptoms including tetany -- repetitive muscle twitching and convulsions and facial muscle spasms that can lead to seizures.
Potassium and Sodium
The two essential electrolytes potassium and sodium work together to balance the level of fluid inside and outside of cells. Most of the potassium ions reside inside of cells, while most sodium remains in the fluid surrounding cells. These two electrolytes form an electrical gradient that transmits nerve signals between cells and a chemical gradient that allows ions to move in and out of the cells. A low potassium level, a medical condition known as hypokalemia, interferes with normal muscle contraction and causes muscle weakness and spasms that can resemble a tremor. Hyperkalemia, too much potassium in the blood, also interferes with nerve impulses, causing an irregular heartbeat, tremors and paralysis.
Your body uses approximately half of the magnesium to build strong bones and teeth. Of the other half, most is found inside of cells. Magnesium stays in the fluid portion of the cell. When muscle cells respond to nerve electrical impulses and release the calcium into the fluid portion of the cell, the magnesium ions produce a small electrical charge that propels the calcium back into the specialized structure of the cell. In doing this, magnesium triggers the cell to relax and get ready for the next contraction. A magnesium deficiency causes numbness and tingling, especially in the hands and feet, sporadic muscle contractions, tremor and seizures.