Mucus

Themucusis a normal, slippery, and stringy fluid substance produced by many lining tissues in the body. It is essential for body function and acts as a protective and moisturizing layer to keep critical organs from drying out. Mucus also acts as a trap for irritants like dust, smoke, or bacteria. It contains antibodies and bacteria-killing enzymes to help fight off infections.

The body produces a lot of mucus -- about 1 to 1.5 liters per day. We don't tend to notice mucus at all unless its production is increased or the quality of mucus has changed, as may happen with different illnesses and conditions.

Mucus is produced in many sites in the body by mucus glands in the lining tissues of multiple organs, including the following:

• Lungs
• Sinuses
• Mouth
• Throat
• Nose
• Gastrointestinal tract

Phlegmis the term that is used to refer to mucus produced by the respiratory system, particularly when excess mucus is produced and coughed up. During an infection, the mucus contains thevirusesorbacteriaresponsible for the infection as well as infection-fighting cells of the body's immune system (white blood cells).

Phlegm itself is not dangerous, but when present in large amounts, it can clog the airways. Phlegm is usually expelled bycoughing, and this is typically accompanied by symptoms likenasal congestion,流鼻涕, andsore throat.

Respiratory infections like colds, theflu, andsinusitisare common causes of increased mucus production andcoughingup mucus.Allergicreactions are another reason that mucus production can increase. Even the consumption of spicy foods can spark excess mucus production in the nasal passages.

When you are sick from arespiratory infection, you may notice thickened mucus that may appear darker than normal. This thickened mucus is harder to clear than typical mucus. This mucus is associated with many of the characteristic symptoms of acoldorflu. The mucus may also appear yellow-green when you are ill.

Excessive mucus is rarely a serious medical problem, but it is uncomfortable and a nuisance, particularly when it blocks sinuses or causes coughing fits. Thickened mucus and excess mucus production cause many unpleasant symptoms including:

• Runny nose
• Nasalcongestion
• Sore throat
• Sinus headache
• Cough

Different colors of mucus and phlegm could mean the following:

• The thickened mucus that accompanies many illnesses is often darker and yellow-colored compared to normal, clear, thin mucus.
• Greenish mucus means that the mucus contains infection-fighting white blood cells.
• Blood-tinged or brownish mucus is also common with upper respiratory infections, especially if the inside of the nose has become irritated or scratched.

While a small amount of blood in mucus is normal, you should see a healthcare professional if there is excessive bleeding.

Saline nasal rinses, including neti pots, are an option for those who would like to get rid of excess mucus without taking medications. Bulb syringes and squeeze bottles are other methods to donasal irrigation. Saline nasal sprays may also be helpful.

All these techniques thin out the mucus and help clear the airways and sinuses. Always use sterile saline rinses that can be purchased, or use distilled, previously boiled, or sterile water to make up the solution. Using non-sterile tap water has a small chance of introducing an infection into the airways and sinuses.

Certain medications are also able to help thin mucus and enhance the body's ability to remove it.

Neti pots and other methods fornasal irrigationwork using the same principle:

• A saline (saltwater) solution is injected into one nostril.
• This loosens up all the mucus in the nasalcavity.
• The water drains out the other nostril.

Be sure that any solution you use for nasal irrigation is made with sterile (such as previously boiled) water.

Severalover-the-counter(OTC) medications can help reduce mucus production or help with the removal of mucus. Decongestants andantihistaminesare two kinds ofdrugsthat may help relieve symptoms of acoldor flu.

Decongestants reduce blood flow to the lining tissues of the nose and throat, so your body may produce less mucus. They may help you breathe easier when you have a stuffy nose, but because they are drying, they may have the unintended effect of thickening the mucus that is present. Decongestants should be used only under physician supervision in persons withhigh blood pressureorheart disease.

Antihistaminesblock or limit the action of histamines, substances produced duringallergicreactions that cause the lining tissues in the nose to produce more mucus. Older or first-generation antihistamines can be sedating, but newer types of antihistamines can be taken during the day with little sedating effect.

An additional kind of medication that can help thin out mucus isguaifenesin.Guaifenesinis a type of drug called an expectorant. Expectorants make the mucus thinner so it is easier tocoughup.