Lips are a visible organ at the mouth of human beings and many animals. Both lips are soft, protruding, movable, and the main function is for food intake, as a tangible sensory organ, and in articulation of speech

One can easily differentiate between the Upper (Labium superiors) and lower lip (Labium inferioris). The lower lip is somewhat larger. The lip skin is not hairy and doesn't have sweat glands or sebaceous glands. So, it does not have the usual protection layer of sweat and body oils which keep skin smooth, kill pathogens, and also regulate warmth. For these reasons, the lips dry out faster and are chapped more easily. It has been seen that the Lips can (temporarily) swell. The reasons for swollen lips are wide-ranging and can be from injuries to side effects of medications or even misalignment of teeth.

The swelling of lips may be of different types depending upon the causes of their occurrence like swollen lips medically termed as Myxedema or Angioedema, lip inflammation known to be as Eczema or Glucagonoma and enlargements of the lips referred  to as Acromegaly or Muccopolysacharidosis. The swelling of lip may also account for some general factors such as allergic reactions within the body or environmental factors such as exposure to excessive heat or cold etc. The allergic reactions may be because of sensitivity to a particular variety of food or beverage. In tropical countries desert regions it is seen that extreme heat & radiation from the sun may damage the lips especially the lower part of it leaving the lips swollen & hard dry. This can also cause the reddening of the lips & increase chances of consequent cancer.

Symptoms & effects of swelling:

In common the inflammation of the lips which turns the lips into red, cracked & scaly with irritation and pain is caused by the deficiency of the essential vitamin B2. This may eventually give rise to vertical skin folds in the corners of the mouth leaving the sufferer unable to open the jaws sufficiently. In case of Acromegaly or Muccopolysacharidosis one may knowledge sudden swelling of the upper part of the lips accompanied by swelling of the lower part of the cheeks with visible formation of lump like structures in the affected region. It may also lead to a painful cracking and bleeding of the lips with a change in the lip color from its usual to a scaly reddish brown like that of a hard rubber. Sometimes the swelling of the lips may occur due to viral infection symptoms of which are formation of painful blisters in both the lips. This condition of lip swelling is known as lip herpes. Carcinoma is the blackening of the lips due to use of tobacco, excessive intake of alcohol and lack of oral hygiene.

Swelling Of the Upper Lips -
A swollen upper lip is a sign of possible stomach disorders, which can include heartburn, over-acidity, and ulcers resulting from tile repeated consumption of sugar, caffeine, spices, alcohol, soft drinks, refined flour, potatoes and other nightshades, and other yin extremes. When the stomach becomes loose and swollen, the muscular valve, the cardiac sphincter at the opening of the stomach relaxes or operates ineffectively. Normally, the sphincter is closed when food is in the stomach. The contents of the stomach, including stomach acid, are regurgitated into the esophagus, causing a burning sensation in the chest as also the neck after a meal. This symptom, commonly known as heartburn, affects millions of people everyday.

Home remedies & prevention:

In general swellings in the lips caused by allergy can be treated without much worries by suitable application of anti inflammatory drugs or ointments such as corticosteroid prescribed by a registered medical practioner. In case if the swelling is a prolonged and is continuing for a period of more than weeks than removal of the swollen part may be done through surgery or radiation therapy. 

Diagnosing What Made Your Upper Lips Swell -

Always check the food that you ate just before this happened if your lips have swollen. It is very much possible that you suffer from some food allergy or that the food you ate caused the problems stated above leading to the swelling. However there can be a few other possibilities. The swelling on the lips can be a result of an allergy of mattresses and pillows you sleep in, because sometimes they are made of some irritating materials and can cause local allergy signs. If the swelling is persistent, then check if some other parts of the body are also swollen. If they are refer to your doctor, at the earliest.