Coughs can be categorized into dry (non-productive) or chesty (productive) coughs. A dry cough occurs when the throat and upper airways become inflamed. Patients cough without producing any mucus or phlegm in a dry cough. They often experience an uncomfortable tickling in the throat that begins the actual attacks of a cough.
Most coughs are acute in nature; they appear suddenly and normally do not last longer than 2-3 weeks. 
What Causes A Dry Cough?
It often occurs at the end of infections such as a cold, flu or a sinus infection, or after a person has been exposed to irritants such as smoke, dust or chemical fumes. 
Smoking cigarettes, allergies, and asthma are also common causes of coughs. 
Infections cause inflammation of the throat and upper airways. A dry cough is an attempt to remove this inflammation but it is usually of no benefit and can be rather uncomfortable. 
In certain cases, a dry cough can be a symptom of a more serious condition such as lung infections like pneumonia or acute bronchitis, chronic obstructive pulmonary disease and sinusitis. 
Chronic, dry cough is a well-known side effect of blood pressure reducing drugs such as ACE inhibitors and beta blockers. If a cough was set off after taking one of these drugs, you are advised to talk to the doctor about changing to a different class of blood-pressure medication.
Homemade Cough Remedies
Drink a lot of warm water during the day to ease a cough. 
You can also drink a mix of lemon juice, honey, and warm water at least thrice during the day.
- Gargles are always effective for easing a dry cough. Add some salt to lukewarm water and gargle.
- Gargling with warm spinach juice is also very helpful in providing relief from a dry cough.
- Alternatively, you also can prepare a concoction of henna leaves for treating a dry cough.
Also, chewing a piece fresh ginger with some salt sprinkled on it can bring relief from a dry cough.  If you find it troublesome to chew raw ginger, then it can be helpful to chop it into fine pieces and to add it to a cup of water. Boil this water till only half a cup remains in the pot. Strain this homemade cough mixture before you drink it. You can add a spoonful of honey to improve the taste. Also, ginger and honey work by coating the throat, reducing irritation and the tickling sensation common in dry coughs.
Eat 3-4 balls of black pepper with caraway seeds and a pinch of common salt. Suck on it for some time to get instant relief from a dry cough. 
Before going to bed, you can drink hot milk with some honey.  Hot milk and honey can provide instant relief from a dry cough and help you get a relaxed sleep.
Grape juice with honey can be a useful remedy for treating a dry cough as well.
Another effective remedy is to mix half a spoon of Cuscus grass in 3-4 teaspoons of coconut milk. Add one teaspoon of honey to it and drink at night before going to bed.
Turmeric, with its natural antiseptic properties, can also be of great help in treating a dry cough. Add a pinch of turmeric to a spoonful of honey and drink it at bedtime. 
Almonds can be an excellent dry cough remedy too. Soak three or four almonds overnight. In the morning, peel the almonds and grind them to a fine paste. Add a few grains of sugar or a spoon of honey to this cough remedy and eat this mixture. It can help you feel better in 2-3 days.
Over The Counter (OTC) And Prescription Drugs For Dry Cough
Relief from a dry, tickling, coughs can be obtained by sucking on cough lozenges or hard candy. (However, it is advised to not to give a lozenge or hard candy to a child under 3 years old because of the associated choking hazard.) Rest and sleep allow the body's natural defense to concentrate on fighting the infection. A non-productive or a dry cough, in which no mucus is coughed up, can be treated with a cough suppressant to reduce the cough reflex.
Common antitussives or cough suppressants include :
They act by blocking the cough reflex. Other cough suppressants include simple linctus, glycerin, and lemon and honey, which coat the throat and provide relief from a dry cough.
Dextromethorphan is a very effective cough suppressant and is one of the most common ingredients in OTC cough remedies. It rarely causes side effects, although an upset stomach or drowsiness may occasionally occur. Codeine, also a very effective cough suppressant, is available only by prescription in many states of the US. Because codeine is a narcotic drug, some people fear that it may be addictive.
Cough suppressants are constituents of many cough remedies that combine many active ingredients to alleviate distinct symptoms.
- Pholcodine Linctus BP 10 mL (10 mg) three to four times a day.
- Codeine Linctus BP 5 mL to 10 mL (15 mg to 30 mg) three to four times a day.
- Codeine phosphate tablets 30 mg to 60 mg every 4 hours.
Some cough remedies also contain substances known as sympathomimetics, such as pseudoephedrine. Pseudoephedrine is the only decongestant used in OTC products. These OTC cough remedies relax the airways and produce decongestant effects. They are also useful in patients suffering from both a blocked nose as well as a cough. 
In some cases, antihistamines  such as Diphenhydramine are advised, which may aid sleep if taken at bedtime. Because these antihistamines cause drowsiness, they should not be taken while driving or performing skilled tasks. They are known to reduce the cough reflex.