A phlegm cough, known as a productive cough, is the body’s natural way of keeping the lungs and airways clear of mucus. Contact your doctor if you're coughing up blood or the cough lasts longer than 10 to 14 days, or if the cough is accompanied by fever, weight loss or a wheezing sound when you inhale. If it's not related to a more serious medical condition, home remedies can help break up the phlegm and quiet the coughing until the illness passes.

Honey

Honey is a popular home remedy for a cough, and with good reason. In 2007, ABC News reported that a study performed by the Penn State College of Medicine found that giving honey to children between ages 2 and 18 before bedtime caused them to sleep better and cough less than those given a traditional dextromethorphan cough syrup or nothing at all 3. Two teaspoons of honey can be taken straight or mixed into hot water or tea. Do not give honey to children younger than 1.

Chicken Soup

The folk remedy of eating chicken soup to cure the common cold has been proven. In the October 2000 edition of the medical journal Chest, a study performed by doctors at the University of Nebraska Medical Center suggests that the chemical properties of chicken soup does help relieve symptoms of a cold. It helps relieve coughs by thinning mucus secretions while slowing white blood cells in the immune system that stimulate an inflammatory response.

Onions and Sugar

Although it may not sound particularly appetizing, onions and sugar are part of a cure for coughing that dates to the Depression era, according to “The Doctor’s Book of Home Remedies.” Chop an entire onion and place it into a bowl. Cover it with 1/2 cup white sugar and allow the mixture to sit overnight. The onions soak up the sugar and make a syrup. To speed the process, simmer the mixture in a pan over low heat for about a half hour. Take one spoonful every two hours.

Herbal Remedies

Herbal remedies for phlegm coughs include Echinacea and peppermint. Echinacea works on viral and bacterial infections, and is sold in tablet form. Peppermint lozenges have menthol action that helps suppress the cough reflex. Both can also be made into a tea with fresh herbs and hot water. Those with autoimmune disorders should avoid Echinacea. Peppermint shouldn't be used by people with gallbladder problems. If you have any medical conditions, consult your doctor before using herbal remedies.

Eucalyptus Oil

Inhaling the vapors of eucalyptus essential oil can quickly help calm a cough. Use the steam inhalation method by adding two or three drops of the oil to a steaming hot bowl of water and inhale the vapors for 10 to 15 minutes. Use caution with eucalyptus oil. It can cause severe allergic reactions if it touches the skin undiluted.