Lithium is a drug commonly used to treat bipolar disorder and depressive disorders. It is a positively charged element or particle that is similar to sodium and potassium. It interferes at several places inside cells and on the cell surface with other positively charged atoms such as sodium, potassium, calcium, and magnesium, which are important in many cellular functions. It interferes with the synthesis and retake of chemical messengers by which nerves communicate with each other (neurotransmitters). It also affects the concentrations of tryptophan and serotonin in the brain. In addition, it increases the production of white blood cells in the bone marrow.

Lithium ion battery is a type of a battery composed of lithium, the lightest metal and the metal that has the highest electrochemical potential. These are made from Lithium ions from chemicals. Because of its lightness and high energy density, lithium-ion batteries are ideal for portable devices.

Lithotomy underbody blanket is designed to deliver full, unrestricted patient access and the flexibility for procedures involving the lower extremities, abdominal, peritoneal, and pelvic cavities. It is usually positioned on the procedure table before the patient arrives to the room. The underbody design provides full-unrestricted access to the patient. The blanket draws up next to the patient when inflated to surround them in warmth.

Lithotripsy Systems are used to disintegrate calculi such as kidney, bladder, ureter or gall stones. Lithotripsy systems use percutaneous or transurethral endoscopic stone removal techniques.

Lithotripter is a device that pulverizes kidney stones and gallstones by passing shock waves through a water-filled tub, in which the patient sits.

A Lithotriptor is a medical device used in the non-invasive treatment of kidney stones (urinary calculosis) and biliary calculi (stones in the gallbladder or in the liver).Lithotripsy attempts to break up the stone with minimal collateral damage by using an externally applied, focused, high-intensity acoustic pulse. The sedated or anesthesized patient lies down in the apparatus' bed, with his back supported by a water-filled coupling device placed at the level of kidneys, for instance. A fluoroscopic x-ray imaging system or an ultrasound imaging system is used to locate the stone and aim the treatment head so that the F1 of the shock wave is focused on the stone. The treatment usually starts at the equipment's lowest power level, with a long gap between pulses, in order to accustom the patient to the sensation. The frequency of pulses and the power level will then be gradually increased, in order to break up the stone more effectively. The final power level will usually depend on the patient's pain threshold. If the stone is positioned near a bone (usually a rib in the case of kidney stones), this treatment may be more uncomfortable because the shock waves can cause a mild resonance in the bone which can be felt by the patient. The sensation of the treatment is likened to an elastic band twanging off the skin, and the patient is shocked in time with his heartbeat (he will be hooked up to an ECG).