Deep, consistent coughs that are tied to respiratory infections are often triggered by mucus that's trapped in your lungs. The mucus is usually quite thick and difficult to dislodge simply by coughing. An expectorant can help thin and loosen the phlegm. Though there are many over-the-counter expectorants available in drugstores, some foods can work as well.
Onions contain irritating compounds that can really trigger productive coughs. There are several different ways that you can ingest onions as an expectorant while you're ill. You could thinly slice an onion and boil it in water or chicken broth to make a clear soup to sip several times a day. The book "1,801 Home Remedies" also suggests making an onion cough syrup. Heat 2 tablespoons of lemon juice and 1 tablespoon of honey until the mixture is just warm, then stir in about 2 teaspoons of grated onion and drink the syrup.
Horseradish's signature burn clears the mucus from your lungs and can be effective in treating other cold symptoms such as a stuffy nose. Grated fresh horseradish is the best for clogged lungs if you can find it, but jarred horseradish will also work in a pinch. You can smear horseradish on crackers and eat it as often as desired to clear up your cough. "Rodale's Illustrated Encyclopedia of Herbs" recommends that those who don't have an appetite make a homemade syrup. To do this, add 1 ounce of horseradish and 1/2 ounce of bruised mustard seeds to 1 pint of boiling water. Steep the herbs for four hours, strain the mixture and take 3 tablespoons three times daily.
Ginger is a pungent herb that loosens mucus, but won't burn going down if you have a sore throat. Crystallized ginger is a pleasant treat to snack on if you have a deep cough. Ginger tea is also an effective expectorant that "1,801 Home Remedies" suggests to those with respiratory infections. Peel and slice fresh ginger root and add it to 8 ounces of boiling water. Simmer the tea for five to 10 minutes, strain the beverage and sip it. Because ginger is relatively mild, you can sip as much of the tea as you desire throughout the day.