Infant crying is often perceived as a signal that something is wrong—a wet diaper, hunger, or perhaps a lingering illness. However, many parents encounter a phase where none of the standard solutions work. This period involves hours of inconsolable screaming, often starting in the late afternoon and lasting well into the night. It can leave the most patient caregivers feeling incompetent, exhausted, and desperate. This phenomenon is known as the PURPLE crying period, and understanding its developmental roots is the first step toward surviving it.

The term was coined to describe a normal developmental phase that most, if not all, infants go through. It is not a medical condition, nor is it a reflection of poor parenting. Instead, it represents a specific window in early human development where the brain and nervous system are navigating a significant transition.

Deciphering the PURPLE Acronym

The word "PURPLE" is not a description of the baby’s skin color during a crying fit, though they may indeed turn quite red. Rather, it is an acronym developed by developmental experts to help parents remember the six core characteristics of this phase.

P: Peak of Crying

Crying typically begins to increase around two weeks of age. It isn't a steady state; it builds in intensity. Most infants hit the absolute peak of this crying behavior during their second month of life. After the two-month mark, the frequency and duration usually begin a gradual decline, finally tapering off by the fourth or fifth month.

U: Unexpected

One of the most frustrating aspects for parents is that this crying comes and goes with no apparent trigger. A baby might be perfectly calm one moment and in full-blown distress the next. Because there is no clear cause, it is impossible to "fix" the situation through traditional means, which is a major source of parental stress.

R: Resists Soothing

During the PURPLE crying period, a baby may not stop crying regardless of what the caregiver does. You might try feeding, changing, rocking, or singing, only to find the crying continues unabated. It is important to realize that the failure of these techniques is not a failure of your care; it is simply a characteristic of this developmental stage.

P: Pain-like Face

Infants in this phase often look as though they are in intense physical pain. They may pull up their legs, clench their fists, and screw up their faces. While it is always wise to rule out medical issues with a pediatrician, in the context of PURPLE crying, these expressions are typically a physical manifestation of a high arousal state rather than an underlying injury or illness.

L: Long-Lasting

This isn't just a ten-minute fuss. Crying bouts during this period can last for 30 to 40 minutes at a minimum, and in many cases, they can persist for five hours or more in a single day. The sheer duration is what often leads to caregiver burnout.

E: Evening

There is a reason this is often called the "witching hour." Crying episodes are most frequently clustered in the late afternoon and evening hours. This coincides with the time of day when parents are often most tired and when the household is at its busiest, creating a perfect storm of environmental and emotional stress.

The Timeline: When Does This End?

The use of the word "period" in this context is intentional. It serves as a reminder to parents that this is a temporary phase with a definitive beginning and end. Research shows that this increased crying usually starts around the second week after birth. It reaches its zenith at six to eight weeks.

By the time an infant reaches three to four months, the crying significantly decreases for the majority of babies. By five months, most families find that the intense, inconsolable episodes have vanished entirely. Knowing that there is a light at the end of the tunnel can be a vital psychological lifeline for parents operating on minimal sleep.

Colic vs. the PURPLE Crying Period

For decades, this behavior was simply referred to as "colic." However, the medical community has shifted toward the "PURPLE" terminology because "colic" often implies that there is something wrong with the baby’s digestion or that the baby is "sick."

Colic was traditionally defined by the "Rule of Three": crying for more than three hours a day, at least three days a week, for over three weeks. While the symptoms of colic and PURPLE crying overlap, the latter emphasizes that this is a normal part of healthy infant development. It moves the conversation away from "How do we treat this illness?" to "How do we support the family through this developmental leap?"

Recent theories suggest this phase may be related to the baby’s developing nervous system and its inability to filter out environmental stimuli. By the end of the day, the infant’s brain may be "overloaded," leading to a discharge of tension through crying. Other researchers suggest it is an evolutionary trait—crying ensured that the infant remained in close physical proximity to the caregiver during the vulnerable evening hours.

Practical Strategies for Managing the Noise

While you may not be able to stop the crying entirely, there are several methods that can help soothe a baby during a PURPLE episode. The goal is often not to silence the baby immediately, but to provide a sense of security and comfort while the phase runs its course.

1. The Power of Proximity

Many infants respond well to increased physical contact. Baby-wearing—using a wrap or carrier—allows the baby to hear your heartbeat and feel your warmth while keeping your hands free. The rhythmic motion of your walking also provides a steady, calming stimulus.

2. Sensory Regulation

Since overstimulation may play a role, reducing the environmental load can be helpful.

  • White Noise: Mimicking the loud, rushing sounds of the womb can be very effective. This can be achieved through a dedicated machine, a vacuum cleaner, or even a running shower.
  • Dimmed Lighting: Reducing visual input can help a baby’s nervous system settle.
  • Rhythmic Motion: A gentle swing, a car ride, or rhythmic patting on the back can sometimes break the cycle of high-arousal crying.

3. Checking the Basics

Even during the PURPLE period, it is essential to ensure the baby isn't crying for a fundamental reason. Check for:

  • Hunger or thirst.
  • Temperature: Ensure the baby isn't too hot or too cold (the chest should feel warm, but not sweaty).
  • Physical Discomfort: Check for a hair tourniquet (a hair wrapped around a toe or finger) or a scratchy clothing tag.

The "Safety First" Rule: When Frustration Peaks

The most critical aspect of managing the PURPLE crying period is the safety of the infant and the mental health of the caregiver. Inconsolable crying is the number one trigger for Shaken Baby Syndrome (SBS), also known as Abusive Head Trauma (AHT).

When a baby has been crying for hours and nothing seems to work, it is natural for a parent to feel anger, resentment, or a loss of control. If you feel your frustration rising to a point where you might lash out or shake the baby, follow these steps:

  1. Put the baby down: Place the infant on their back in a safe sleep space, such as a crib or bassinet. Ensure there are no loose blankets or toys.
  2. Walk away: Leave the room and close the door. The baby is safe in the crib, even if they are still crying.
  3. Take five: Go to another room, get a glass of water, listen to music, or take deep breaths. Give yourself at least 5 to 10 minutes to de-escalate.
  4. Check back: Once you have regained your composure, go back and check on the baby. If you still feel overwhelmed, call a friend, a family member, or a support hotline.

It is better for a baby to cry alone in a safe crib for ten minutes than to be in the arms of a parent who has lost their emotional regulation.

Supporting the Caregiver

Postpartum depression and anxiety can be exacerbated by the PURPLE crying period. It is difficult to bond with an infant who screams for several hours a day. If you are struggling, it is vital to speak with a healthcare provider.

Furthermore, the "village" approach is essential during these months. If friends or family offer to help, accept it. Let them hold the baby for an hour while you take a nap or a shower. If you are the partner of the primary caregiver, recognize that the evening hours are a period of high stress; stepping in to take over soothing duties can prevent burnout.

When to Consult a Professional

While PURPLE crying is normal, there are instances where crying may indicate a medical problem. You should contact your pediatrician if you notice any of the following "red flags":

  • Fever: Any fever in an infant under three months is an emergency.
  • Projectile Vomiting: This is different from standard spit-up and may indicate a digestive blockage.
  • Changes in Stool: Blood or mucus in the stool requires medical evaluation.
  • Lethargy: If the baby is too weak to cry or isn't waking up for feedings.
  • Poor Weight Gain: If the infant isn't hitting their growth milestones.

If your gut instinct tells you that something is wrong, always seek a professional opinion. A pediatrician can help confirm that the baby is healthy, which in turn can provide you with the mental peace needed to navigate the PURPLE period.

Final Thoughts: This Too Shall Pass

The PURPLE crying period is a challenging rite of passage for new parents. It tests your patience, your physical endurance, and your confidence. However, it is a sign of a developing, healthy brain that is learning to process the world.

By renaming this experience from "colic" to a "period," we shift the narrative. We acknowledge that the crying is a temporary phase—a bridge between the newborn days and the more interactive, social months that follow. Focus on safety, prioritize your own mental health, and remember that as your baby grows, their ability to communicate will move beyond these inconsolable tears. In a few months, the "witching hour" will be replaced by smiles, babbling, and a much-needed sense of calm.