After a week and a half battle with a cough, my partner was diagnosed today with pneumonia. Fortunately he's feeling better than he has been, and I haven't caught it from him (knock on wood). Yesterday I diffused a combination of eucalyptus and lemon essential oils into the air to help fight the infection.
Eucalyptus oil is believed to act as an expectorant and a decongestant, so it is particularly beneficial in treating coughs. It is reputed to help generate lung tissue and has been used as a traditional remedy for asthma, bronchitis, colds and other ailments. It is at once antibacterial, antifungal and antiviral. Lemon oil is both refreshing and antiseptic.
Like other essential oils, eucalyptus oil and lemon oil can be applied in a variety of ways, including topical application to the skin if diluted in a carrier oil such as jojoba or sweet almond oil. I chose to diffuse the oil into the air so that it would benefit both of us as well as clean the air in our apartment. However, all three of our cats were staying at my mother's. Had the cats been home I most likely would have chosen a more direct form of application as essential oils which are safe to humans can be toxic to pets. Cats, especially, are sensitive to many components of essential oils. One book I highly recommend to learn more about essential oil safety and pets is Holistic Aromatherapy for Animals.
If you'd rather not subject your entire home to the aroma of eucalyptus, another way to benefit is to put a few drops of the oil in a bowl of steaming water. Cover your head with a towel, and lean over the bowl so that you are effectively in a tent with the water and inhale the steam for 5-10 minutes.