Eucalyptus oil has many benefits and uses, including:

1. Relieving pain and inflammation: Eucalyptus oil can help reduce pain and inflammation associated with many conditions, such as arthritis and muscle and joint pain.

2. Clearing congestion: Eucalyptus oil can be used to relieve nasal congestion and sinus tension by inhaling steam with added eucalyptus oil. It reacts with mucous membranes, reducing mucus and helping to loosen it so that it can be coughed up.

3. Killing bacteria and viruses: Eucalyptus oil contains substances that kill bacteria, viruses, and fungi. It can be used as a natural disinfecting air spray, removing bacteria, viruses, and mold from the environment.

4. Relieving respiratory conditions: Eucalyptus oil can help relieve respiratory conditions such as asthma and sinusitis by reducing mucus and blocking asthma symptoms. However, for people who are allergic to eucalyptus, it may worsen their asthma.

5. Promoting wound healing: Eucalyptus oil can be used on minor burns or other injuries that can be treated at home to fight inflammation and promote healing.

6. Preventing mosquito bites: Eucalyptus oil can be used as a mosquito repellent.

7. Cleaning: Eucalyptus oil is the active ingredient in more than 30 cleaning products approved by the EWG, a nonprofit environmental research group. In one study, it removed bacteria including E.coli from steel surfaces.

8. Freshening the air: Eucalyptus oil can be used as an anti-microbial, non-toxic air freshener that removes bacteria, viruses, and mold from the environment.

9. Preventing plaque and gum disease: Eucalyptus oil is rich in cineole, an antiseptic that kills the bacteria that can cause bad breath. Some antiseptic mouthwashes use eucalyptus along with other oils and have been shown to help prevent plaque and gingivitis.

It is important to note that undiluted eucalyptus oil can be highly toxic if taken by mouth. It should be diluted before use and should not be ingested at its full strength.