Under typical circumstances, liposuction is a very safe procedure and the side effects are often mild and temporary. The most common liposuction side effects include bruising, swelling and some soreness around the treatment area. This is a normal part of the healing process and the symptoms are temporary and will away with time. Other side effects include various forms of skin discoloration such as hyper pigmentation and hematomas or seromas. These side effects can be a little scary for some patients but will also eventually go away with time.
Bruising, Swelling, Soreness
Bruising and swelling are some of the minor side effects immediately following liposuction surgery that can cause the treated area to feel tender and a little pain. Most bruises and swelling will go away within a short period of time and generally last no longer than a month. 
The actual duration and severity of these side effects will depend largely on many factors such as the size of the procedure, how well the surgeon drains the treated area of leaked fluids before closing the incision, and how well the patient takes care of themselves during the recovery period. To help get through the discomfort that might accompany the healing process, it is not uncommon to receive some prescription pain medication and antibiotics to minimize the risk of infection.
Liposuction Scarring
Whenever the skin heals after an injury or in this case an incision, a fibrous tissue replaces the normal skin. Just about every wound results in scarring it is just a matter of how visible the scar is. With newer liposuction techniques that require smaller incision, the risk of scarring has been dramatically reduced. Nonetheless, it is still a possibility with any surgical procedure including liposuction. Despite being less ideal aesthetically, a liposuction scar is not a health risk in any way. There are even skin resurfacing treatments available these days that can eliminate most scars.
Skin Necrosis
Skin necrosis occurs when the supply of vital material essential to the skin cells are cut off due to damaged blood vessels or a blood clot. The skin cells will naturally die and create full thickness skin necrosis. In itself this is not a dangerous side effect but it can become a serious medical problem if an infection occurs in the area.
Hyper Pigmentation
This is not a lethal side effect but can last for as long as several years depending on the individual’s skin tone. Hyper pigmentation occurs when a skin cell ruptures and releases melanin. The melanin is the pigment that creates the discoloration as it is captured by the macrophage of neighboring skin cells. Patients with darker skin tones can expect any case of hyper pigmentation to last longer than someone with fair skin.
Hematomas and Seromas
Hematomas and seromas are variations of skin discoloration caused by the pooling of blood under the skin. This will naturally go away as the body removes the excess pooled red blood cells but can last several months depending on the severity of the situation. The chances of this side effect occurring and the severity can be minimized by the plastic surgeon if the treated area is properly drained of all leaked fluids before the incision is closed.
Thrombophlebitis
This is a situation where a blood clot occurs in a vein by pieces of dislodged fat during liposuction surgery. It can cause the area to swell or become inflamed and is more common in particular treatment areas such as the thighs. In mild cases the discoloration will go away in a matter of weeks. It can become a serious problem if the clot occurs in other areas such as the lungs. Any patient experiencing difficulty breathing or any respiratory problems during the few days following liposuction surgery should consult their physician.
Many of the common side effects of liposuction are usually mild in nature and are temporary. Some of these liposuction side effects such as skin necrosis and hematomas or seromas are more commonly associated with traditional liposuction techniques. The development of new methods have significantly reduced some side effects such as scarring and lowered the amount of pain experienced by the recovering patient.