If you have seizures/epilepsy avoid the following oils:
Fennel, Hyssop, Rosemary, Sage and Thyme.
If you are Pregnant avoid the following oils:
Aniseed, Angelic, Basil, Birch, Black Pepper, Camphor, Carrot Seed, Cassia, Cedarwood, Chamomile, Cinnamon, Clary Sage, Clove, Coriander, Fennel, Ginger, Hyssop, Jasmine, Juniper, Lemongrass, Marjoram, Melissa, Myrrh, Nutmeg, Oregano, Peppermint, Pine, Rockrose, Rose, Rosemary, Sage and Thyme.
If you have High Blood Pressure avoid:
Pine, Rosemary, Sage and Thyme.
If you have Kidney Problems avoid:
Juniper, Sandalwood and Coriander.
Essential oils that can cause skin sensitivity or irritation:
Allspice, Basil, Benzoin, Black Pepper, Cassia, Cinnamon Bark, Clove, Fennel, Ginger, Lemon, Lemongrass, Lemon Verbena, Oregano, Peppermint, Pine, Tagetes and Thyme.