Glossary Of Terms - L

Lactose, sugar Lansoprazole Larynx Lateral LDL cholesterol Left circumflex
Lesion Life expectancy Linoleic acid Linolenic acid Lipid Lipid-lowering agent
Living will, under consent Lotion Low-fat spreads under fats Lung Lymphocytes

LA = left atrium.

Lacrimal duct See tear duct.

LAD means Left anterior descending. See coronary arteries.

Lancet The Lancet is a journal for UK doctors.

Lansoprazole is a proton pump inhibitor drug to reduce the amount of acid produced in the patient's stomach. It is given to patients who get stomach or duodenal irritation eg from high doses of aspirin. It is normally taken half an hour to an hour before a meal. Typical treatment to cure conditions such as below is 30mg once daily for about four weeks. Typical treatment to stop it occurring again is 15mg daily.

Lansoprazole can heal the oesophagus (gullet) if it is damaged or inflamed; heal stomach ulcers; relieve the symptoms of NSAIDs and prevent the patient getting stomach ulcers from NSAIDs; treat pain such as heartburn; or indigestion; treat patients whose stomach makes too much acid; and/or treat a bacterial infection caused by heliobacter pyloir, which can cause inflammation of the stomach.

Larynx is the voicebox, in the neck. Sound is produced, with control of the pitch and the volume, eg to make speech. The volume is also partly controlled by the rate at which the person is breathing out.

During swallowing, the epiglottis (a flap attached to the back of the tongue) is pushed over the opening of the larynx by a backward movement of the tongue, thus preventing any food being swallowed from getting into the trachea (windpipe) and to the lungs.

Lateral means side, eg one side of the body. Contralateral means opposite side.

LDL. See Cholesterol LDL under Cholesterol.

Left anterior descending LAD. See Coronary arteries.

Left circumflex LCX. See Coronary arteries.

Left ventricle. See under Ventricle.

Left ventricular heart failure. For left ventricular heart failure see under Heart failure terms.

Lesion has two meanings.

1 It is an injury, eg a wound.

2 It is a structure change that results from disease or injury. Eg see peptic ulcer.

Libido is the desire for sex.

Life expectancy, pensions, insurance. Anthony Robin & Richard Maddison have written articles on these issues in the BCPA J152 (Feb 2007) and J169 (Dec 2009).

Lipid. Lipids are any of a group of organic compounds that are esters of fatty acids or closely related substances. Generally they do not dissolve in water. but are soluble in some other organic solvents. See also lipid under organic chemistry.

An ester is any of a group of compounds produced by a reaction between acids and alcohols and with elimination of water. Fats are solid esters, and a subgroup of the lipids.

Lipid-lowering agent means a drug that reduces raised cholesterol. The longterm aim is to reduce the Cholesterol LDL, as explained under Cholesterol, lipid, and statins.

They reduce the amounts of various fats in the blood – either by interfering with the absorption of bile salts in the bowel, or by altering the way the liver converts fatty acids in the blood into various different lipids.

Some lipid-lowering drugs bind to bile salts in the intestine and prevent them from being reabsorbed. This reduces the bile salts in the blood and triggers the liver to convert more cholesterol into bile salts – thus reducing the level of cholesterol.

Three types of lipid-lowering drugs are:

- Statins (atorvastatin, simvastatin, rosuvastatin, pravastatin etc), which are the most potent and widely used group of drugs to treat high cholesterol levels. Statins work mainly by blocking the action in the liver of an enzyme that is needed for making cholesterol.

- Fibrates (bezafibrate, fenofibrate, ciprofibrate etc) do the same. They act on the liver in a slightly different manner from statins, and are particularly good at decreasing high levels of triglycerides (common types of fats that are essential in normal amounts but can cause health problems at higher levels).

- Ezetimibe (generic name) reduces cholesterol by preventing absorption from the small intestine.

Fish oils are also widely used to help reduce blood lipid levels either as dietary supplements or as 1-2portions of oily fish.

Lone atrial fibrillation. See lone atrial fibrillation under AF.

Living will. This is a statement made by a person before their health deteriorates badly, about what they would like or not like as regards treatment and/or care if their health were to deteriorate. See Consent and Refusal.

Lotion is a liquid to apply to the skin.

Low-density lipoprotein, LDL. See Cholesterol LDL under Cholesterol and see statins.

Low output heart failure. For low output heart failure see under Heart failure terms.

Lung. The lungs are the two respiratory (for breathing) parts of the body in the chest. They are the interface where oxygen from the air passes into the blood, and carbon dioxide CO2 is removed from the blood to the air breathed out.
The trachea, also called the windpipe, is the tube that carries air to and from the lungs. It goes down from the larynx and divides into two to the two bronchi. A bronchus further divides into many smaller branches. Bronchial tube means a bronchus and/or any of the smaller and smaller tubes that it branches into. Respiratory tract means the bronchi and lungs.
Each lung has three parts – eg the right upper lobe, right middle lobe, and right lower lobe. The lower lobes are just above the diaphragm. Each pleura (plural pleurae) is a thin serous (containing serum – a clear watery liquid) membrane that encloses each lung and forms a lining to the chest cavity. The lungs and pleurae are inside the ribs. The arteries and veins that carry the blood between the heart and the lungs are called pulmonary arteries and pulmonary veins.

Lymph is a body fluid containing white cells. Lymphatic is the adjective meaning of lymph or of the system that transports lymph. A lymph node is an organ that filters microorganisms and other particles from lymph. For lymphocytes, a particular kind of white blood cell in the immune system, see under Antibodies.


This information was created and edited by Richard Maddison for the BCPA.
Copyright © 1997-2019 The British Cardiac Patients Association, and/or Richard Maddison.
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First published in this form 2002, and updated 2005, 2007, 2008, 2011, 2012, 2013, 2017.
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Authors, sources and acknowledgements

The main sources are BCPA Journal published articles, other information from authors, and publicly available documents and websites. In many cases the journal articles give sources and further information than the Glossary entries.

Parts of the wordings under ECG and Echocardiogram are adapted with permission from BUPA's health information resources, available at

We hope we have thanked everyone.

Richard Maddison

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