~ What are Entities? ~
Entities are spirits that need to attach to living beings in order to continue in this world. We're not just talking here about people with an obvious spirit problem - e.g. a poltergeist, or when you can feel another presence, like a sudden coldness. Here we are talking about spirits that you're not consciously aware of too.
Entities are really easy to pick up. You will find them anywhere. The best way to protect yourself from entities connecting with you is to keep yourself strong, healthy and happy :o) Certain crystals are particularly good for protection too, so if you're feeling vulnerable it wouldn't hurt to carry one or two around with you. For example, Hematite and Tiger's Eye are particularly grounding and protective.
Negative entities (like any other negative attachment) lower our vibrations, and seem to irritate the trait they are attached to so that we find it hard to let go of the trait, and instead go further in that direction. So if 'anger' is the trait, then with an entity attached to our anger, we cannot break from this feeling, and instead have higher flare ups of anger.
The best way to remove an entity (and any other attachments) is to also work on healing what drew the entity to you in the first place. If I can heal the energetic imbalance enough to remove the entity then the entity can be fully removed. This type of combined healing and clearing is very effective.
Post-clearing I strongly recommend further healing, to continue to work on healing your energetic imbalance so that another entity/attachment cannot reattach to the same problem if it peaks again, or to other energetic imbalances you may have that could be leaving you vulnerable to other attachments.