Baby colic, also known as infantile colic, is defined as episodes of crying for more than three hours a day, for more than three days a week, for three weeks in an otherwise healthy child. Often crying occurs in the evening. It typically does not result in long-term problems. The crying can result in frustration of the parents, depression following delivery, excess visits to the doctor, and child abuse. Baby colic, also known as infantile colic, is defined as episodes of crying for more than three hours a day, for more than three days a week, for three weeks in an otherwise healthy child. Often crying occurs in the evening. It typically does not result in long-term problems. The crying can result in frustration of the parents, depression following delivery, excess visits to the doctor, and child abuse. The cause of colic is unknown. Some believe it is due to gastrointestinal discomfort like intestinal cramping. Diagnosis requires ruling out other possible causes. Concerning findings include a fever, poor activity, or a swollen abdomen. Fewer than 5% of infants with excess crying have an underlying organic disease. Treatment is generally conservative, with little to no role for either medications or alternative therapies. Extra support for the parents may be useful. Tentative evidence supports certain probiotics for the baby and a low-allergen diet by the mother in those who are breastfed. Hydrolyzed formula may be useful in those who are bottlefed. Colic affects 10–40% of children. It is most common at six weeks of age and typically goes away by six months of age. It rarely lasts up to one year of age. It occurs at the same rate in boys and in girls. The first detailed medical description of the problem occurred in 1954. Colic is defined as episodes of crying for more than three hours a day, for more than three days a week for at least a three-week duration in an otherwise healthy child. It is most common around six weeks of age and gets better by six months of age. By contrast, infants normally cry an average of just over two hours a day, with the duration peaking at six weeks. With colic, periods of crying most commonly happen in the evening and for no obvious reason. Associated symptoms may include legs pulled up to the stomach, a flushed face, clenched hands, and a wrinkled brow. The cry is often high pitched (piercing). An infant with colic may affect family stability and be a cause of short-term anxiety or depression in the father and mother. It may also contribute to exhaustion and stress in the parents. Persistent infant crying has been associated with severe marital discord, postpartum depression, early termination of breastfeeding, frequent visits to doctors, and a quadrupling of excessive laboratory tests and prescription of medication for acid reflux. Babies with colic may be exposed to abuse, especially shaken baby syndrome. The cause of colic is generally unknown. Fewer than 5% of infants who cry excessively turn out to have an underlying organic disease, such as constipation, gastroesophageal reflux disease, lactose intolerance, anal fissures, subdural hematomas, or infantile migraine. Babies fed cow's milk have been shown to develop antibody responses to the bovine protein, causing colic. Studies performed showed conflicting evidence about the role of cow's milk allergy. While previously believed to be related to gas pains, this does not appear to be the case. Another theory holds that colic is related to hyperperistalsis of the digestive tube (increased level of activity of contraction and relaxation). The evidence that the use of anticholinergic agents improve colic symptoms supports this hypothesis. Psychological and social factors have been proposed as a cause, but there is no evidence. Studies performed don't support the theory that maternal (or paternal) personality or anxiety causes colic, nor that it is a consequence of a difficult temperament of the baby, but families with colicky children may eventually develop anxiety, fatigue and problems with family functioning as a result. There is some evidence that cigarette smoke may increase the risk. It seems unrelated to breast or bottle feeding with rates similar in both groups. Reflux does not appear to be related to colic.