Babies who have regular bouts of intense crying, however, may be diagnosed with colic. Colic is defined as continual or persistent crying without any apparent reason, typically lasting between 2 and 4 hours a day for at least 5 days a week. It usually begins at around 2 or 3 weeks of age, and subsides on its own by 12 weeks. Colic is not uncommon - it's estimated that as many as 1 in 5 babies have this condition. Babies with colic have prolonged bouts of intense, high-pitched crying.
Some infants draw their legs up and clench their fists, as if in pain.
Spells of crying tend to occur at around the same time each day, often in the early evening. In spite of persistent crying, these babies do not have any apparent symptoms of illness. If bouts of crying are accompanied by vomiting, abdominal bloating, fever, or other signs of unwellness, it should be reported to a doctor immediately. Parents of a colicky baby may be relieved to find out that, however alarming the bouts of crying are, colic itself is not a serious condition. Though they may appear to be in distress, babies with colic are usually in good health.