Cosmetic surgery, or cosmetic procedures and plastic surgery are terms which are often incorrectly used interchangeably. Similarly, people often incorrectly refer to Cosmetic Surgeons and Plastic Surgeons as being the same qualification. However, there is a difference.
Generally speaking, plastic surgery is usually carried out for medical reasons- examples include: skin grafts where healthy skin is taken from one part of the body to replace an area of skin which has been damaged as a result of a burn, cleft lip and palate repair, reconstructive surgery to restore functionality, breast reconstruction surgery following mastectomy etc.
A Plastic Surgeon is a surgeon who has undergone specialist, advanced training and who is registered as a specialist in their field with the Medical Council of Ireland. http://www.medicalcouncil.ie 
Generally speaking, the term cosmetic procedures refer to procedures which are carried out for aesthetic reasons to increase self-esteem. Cosmetic procedures are often performed by doctors, nurses and dentists. However, certain procedures, particularly dermal fillers, can also be performed by beauty therapists who are entirely unregulated. This can be problematic. The administration of dermal fillers is not without risk even when performed by a suitably qualified practitioner. Minor complications include allergic reaction, migration of filler, itching swelling, discomfort and a lumpy, uneven appearance.  More serious complications, though rare, can arise if filler is injected directly into the vascular supply, or in a manner which compresses the vascular supply. Such complications can include: death of tissue (necrosis), blindness or visual impairment and even embolism or stroke.

Examples of cosmetic procedures include:

You may have grounds to recover compensation if:

the procedure, or aftercare, was not carried out to the level of skill expected of a practitioner of like qualification and skill, faced with the same set of facts at the same time and as a direct result of this substandard care, you suffered injury.
Medical negligence may also arise where you were not advised regarding the risks of the procedure in advance and had you been properly advised, you would not have elected to undergo the procedure and would have avoided the risk of injury which you ultimately suffered; or where the product used during the procedure was defective causing you injury.