There are a few things you should be aware of regarding essential oils before you jump right in and you should always consult a doctor before starting any new health regime because, shockingly, I am not a doctor.

What is good for one body, may not be great for another. As a general rule of thumb, essential oils (neat) should never be used directly on the skin and never taken internally. For example, lemon is a natural goo gone. If its dissipating sticky stuff, imagine what it may do to all your digestive tubes over time.
If you do get into a situation where a neat application occurs and you experience sensitization or worse, burning in your eye, flush with a carrier oil. When it starts burning, remember, its oil; and you don't put out a grease fire with water! Also know that sensitization to an oil can occur suddenly and unexpectedly. I discovered by accident that vetiver neat removed a spot of psoriasis on my hand almost instantaneously. When I started experimenting on other spots I quickly discovered this little fun fact and needed some major coconut oil to the rescue!
Although the blends I make are diluted to levels unlikely to cause harm, always test a small patch of skin first. T
There are additional risks associated with conditions such as but not limited to: heart trouble, seizures, high blood pressure, children, elders, animals and pregnancy.
Essential oils are not drugs. Sure they can be used to support specific conditions, but instead of working like a band-aid (drugs) to smother a situation and likely throw another off balance, they work at the cellular, energetic levels to support holistic health. As you learn more about them you will also discover a single oil will support many different conditions, also unlike synthetic solutions you may receive from your doctor.
In general, be mindful that citrus oils can cause photo sensitivity.