COPD, or chronic obstructive pulmonary disease, is a progressive disease that makes it hard to breathe. "Progressive" means the disease gets worse over time. COPD can cause coughing that produces symptoms like large amounts of mucus, wheezing, shortness of breath, chest tightness, and other symptoms.

Cigarette smoking is the leading cause of COPD. Most people who have COPD smoke or used to smoke. Long-term exposure to other lung irritants—such as air pollution, chemical fumes, or dust—also may contribute to COPD. Unlike Asthma, the inhalation treatment in COPD does not give dramatic relief from the symptoms. This usually disheartens the patient who is looking for a cure of COPD symptoms. He then starts questioning the role of inhalers in his COPD treatment.

Inhaler devices used for COPD treatment:
Different inhaler devices suit different people. They can be divided into four groups.

• Pressurized metered dose inhalers (MDIs).
• Breath-activated inhalers - MDIs and dry powder inhalers.
• Inhalers with spacer devices.
• Nebulizers.

Pressurized metered dose inhalers (MDIs): It contains a pressurized inactive gas that propels a dose of drug in each 'puff'. Each dose is released by pressing the top of the inhaler. This type of inhaler is quick to use, small, and convenient to carry. It needs good co-ordination to press the canister, and breathe in fully at the same time.

Breath-activated inhalers: Accuhaler, Twisthaler, Turbuhaler, Revolizer, Diskhaler and Flexhaler are all breath-activated dry powder inhalers. You need to breathe in fairly hard to get the powder into your lungs.

Spacer devices: Spacer devices are used with pressurized MDIs. There are various types - an example is shown opposite. The spacer between the inhaler and the mouth holds the drug like a reservoir when the inhaler is pressed. A valve at the mouth end ensures that the drug is kept within the spacer until you breathe in. When you breathe out, the valve closes. You don't need to have good co-ordination to use a spacer.

Nebulizers: Nebulizers are machines that turn the liquid form of your short-acting bronchodilator medicines into a fine mist, like an aerosol. You breathe this in with a face mask or a mouthpiece. Nebulizers are no more effective than normal inhalers but they are extremely useful in people who are very fatigued (tired) with their breathing, or people who are very breathless. Nebulizers are used mainly in hospital for severe attacks of COPD when large doses of inhaled drugs are needed.

Source: www.cdc.gov