Does your sweet infant, every day around 6pm, turn into a tomato-faced, Thor-like God of Squalling whose paroxysms and noise have you slavishly considering a human sacrifice to appease him?  We’ll make it quick so we don’t keep you from your baby deity: Here’s everything you need to know about colic in babies.

Fast facts: What is colic in babies?

• Colic isn’t a condition or a diagnosis. It is just another word for extreme, frantic crying – defined by some doctors as unsoothable crying for three hours a day, for three days a week, for three weeks in a row; and by others as any crying “that interferes with child development or causes problems in the family.”
• In most babies, this kind of crying is a normal, developmental milestone. It’s also temporary, peaking around 6 weeks and disappearing in the third or fourth month. Which means …
• There are no remedies for colic (sorry, hang in there), though this article does include soothing tips for when your baby is crying uncontrollably.
• In a small percentage of colicky babies, the unconsolable crying is linked to a physiological problem and there should be other signs of physical distress like diarrhoea, vomiting, etc. If you see any physical symptoms of illness, consult a pediatrician immediately.

Still awake? Here is a more detailed look at doctors’ understanding of why some babies scream like a geriatric cult leader the night before the Rapture.

If your baby won’t stop crying, congrats, you’ve reached a developmental milestone.

Until recently, most pediatricians considered colic to be a physical condition, the unsoothable crying indicative of invisible gastric distress like cramps, gas, or acid reflux. But according to Dr. Ronald G. Barr, a leading authority on colic with the University of British Columbia in Vancouver, that is no longer the case. Dr. Barr says the vast majority of babies who cry all of the time are perfectly healthy; gastric distress or an allergy to cow’s milk or formula is rare. Instead, studies of infants all over the world show that unconsolable crying is a natural stage in babies’ development (and a trial by fire, if you will, of their parents).

It’s important to note not every cry is a colicky, unsoothable cry. Dr. Barr estimates 60% of a baby’s crying in this stage is general, yet soothable fussiness; 30% is due to upset like hunger, feeling hot or feeling overtired; and the final 10% — which of course feels like 100% to the bleary-eyed parents dealing with it – is genuinely unconsolable; nothing you do will get the baby to stop crying. This kind of crying peaks at around six weeks, during a time of major brain development in infants, and tapers off sometime in the third or fourth month of a baby’s life, a timing that has given rise to a popular theory for why babies cry unconsolably called the “Fourth Trimester.”

The Fourth Trimester theory, proposed by Dr. Harvey Karp, a pediatrician with the University of Southern California, suggests that human babies are born immature due to physiological constraints; the additional three months necessary to their development would mean babies’ heads would grow too large to fit through their mothers’ birth canal.

Dr. Karp says this Fourth Trimester is a period of rapid brain development. During this time, infants learn to observe and pay attention (and turn off their attention) which allows them to absorb so much new information their brains increase in size by roughly 20% in 10 weeks.

Most babies, Dr. Karp says, have no or little trouble learning this. But for some babies – babies who “have colic” – the ability to switch on and off their attention is difficult, and the three months after birth – the “Forth Trimester” – is a huge challenge. (Who hasn’t cried in the face of a seemingly insurmountable obstacle?)

Dr. Karp’s solution isn’t, as many doctors advocated in a previous age, to “cure” colic in babies by removing all stimulation from their environment. Rather, if a bay is crying uncontrollably, Dr. Karp suggests adding stimulation – of a specific sort reminiscent of the womb.

“Fussy babies would really benefit if they could hop back inside the uterus whenever they get overwhelmed,” Dr. Karp said in a 2005 interview with the New York Times. “Our culture believes in the strange myth that a baby wants to be left in a quiet dark room. But what is this stillness for a newborn baby? It might be aversive, since the womb is jiggly and noisy.”

In an attempt to replicate a womblike environment, Dr. Karp developed a series of steps parents can use for soothing a colicky baby. A quick Google of his “Five S’s,” as the steps are called, finds many parents swearing by their success in soothing colicky babies. But it should be noted that Dr. Karp’s method is simply the most popular, not necessarily proven; a 2010 study found no statistical difference in the amount of crying between babies who were soothed by methods similar to Dr. Karp’s and babies who experienced routine infant care.

Still, you’re probably at the point where you’ll try anything to soothe the baby screaming like a banshee sugar-fiend who just discovered the new soda tax applies to the undead as well as the living. So, here’s a quick and dirty guide to Dr. Karp’s Five S’s for how to get a baby to stop crying uncontrollably.

How to soothe a colicky baby, according to Dr. Harvey Karp

Step 1: Swaddle

Use a large, light-weight blanket to wrap the baby’s arms snuggly but allow their hips to be relaxed.

Step 2: Side or Stomach position

While babies should be put to sleep only on their backs (any other sleep position puts them at risk for SIDS), Dr. Karp says holding babies on their side or stomach-to-your-shoulder is best for calming them.

Step 3: Shushing

Karp says the sound of blood flow in the womb is louder than a vacuum cleaner – so, making steady shushing sounds (not hissing sounds) is the most similar white noise infants are familiar with.

Step 4: Swinging

This means making small, quick, and gentle bouncy motions that imitate the jiggle of a womb, while supporting the baby’s head and neck. This does not mean shaking the baby.

Step 5: Sucking

Karp calls this “the icing on the cake” for fussy babies. Sucking on a pacifier or a parent’s clean finger can help a colicky baby relax.

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Finally, while unsoothable crying in babies is almost always a normal part of development, there is, of course, the chance that frantic screeching may be caused by actual pain or illness. There’s never any shame in consulting a paediatrician if you have concerns about your baby’s crying.