Why Is My Baby Crying? The 5 Main Reasons — and What to Do

The 5 Main Reasons Babies Cry

Newborns cannot talk. Crying is the only tool they have to tell you something is wrong. Most of the time, the reason falls into one of five categories.

The Week 3 Fussy Period (魔の3週目)

Around the third week of life, many parents notice a sudden and dramatic increase in crying. A baby who seemed settled suddenly screams for hours, won't sleep easily, and wakes moments after being put down. This is so common in Japan that it has a name: 魔の3週目 (ma no san-shuume) — roughly translated as "the devil's third week."

What's happening? Your baby's nervous system is developing rapidly. Their ability to sense the world around them — light, sound, sensation — increases faster than their ability to process it. Everything feels more intense. The result is a baby who is harder to settle than they were just days before.

A few things to know:

• It is temporary. The fussy period begins around week 3, peaks at around 6–8 weeks, and gradually eases by 3–4 months.
• It is not your fault. You haven't done anything wrong — this is normal neurological development.
• Feeding and diaper changes alone may not stop the crying. Your baby is not necessarily hungry — they are overstimulated.

The 3-Month Fussy Period (魔の3カ月)

Around 3 months, crying patterns shift again. By this age, your baby has become much more socially aware — they recognise your face and voice, smile at you, and are beginning to understand that when they cry, you come. This awareness is a milestone. But it also means their demands become more specific and harder to predict.

The most common challenge at this stage is night crying. Many babies who slept reasonably well begin waking more at night around 3 months. This isn't regression — it's development. As babies become more aware of the world, the boundary between sleep and wakefulness becomes more interesting to explore.

• Daytime crying often has a clear reason — boredom, hunger, or wanting interaction.
• Night crying at this stage is frequently about routine and habit rather than hunger or discomfort.

How to Comfort a Crying Baby

Once you've checked the basics — hunger, diaper, temperature — and your baby is still crying, these techniques can help.

• Hold and rock — Pick your baby up and gently rock them in your arms. The motion mimics the movement they felt in the womb. Swaying from side to side (not up and down) is often most effective.
• White noise — Low, consistent sounds like a running tap, fan, or white noise app can be remarkably calming. The womb is loud — silence can feel unsettling to newborns.
• Go outside — A change of environment and fresh air often interrupts a crying cycle. Even a short walk in the baby carrier or stroller can help.
• Skin-to-skin contact — Hold your baby against your bare chest. This regulates their body temperature and heart rate and provides deep reassurance.
• Music or gentle singing — A calm, repetitive melody — even humming — can provide the predictability your baby craves. The specific song doesn't matter; consistency does.
• Reduce stimulation — If your baby is overstimulated, less is more. Dim the lights, reduce noise, and hold them close without talking or moving too much.

Night Crying

Night crying is one of the most exhausting experiences of early parenthood. Understanding what's happening can make it a little easier to manage.

In the first 6–8 weeks, newborns have no concept of day or night. Their sleep is driven by hunger, not the clock. Night feeds and waking are completely normal and expected.

Around 2–3 months, a day/night rhythm begins to form — but it's fragile and inconsistent. When your baby wakes and cries at night, take a breath before responding:

• Wait a moment — Give your baby 1–2 minutes before picking them up. Babies often make sounds between sleep cycles that settle on their own. Rushing in every time can actually interrupt the process of learning to self-settle.
• Check quietly — If they continue crying, go in and check without turning on bright lights or making it stimulating. Pat or shush gently without picking up if possible.
• Feed if needed — In the early weeks, night hunger is real. If it's been 2–3 hours since the last feed, feed them.

Night waking does improve with time. Most babies develop longer sleep stretches naturally between 3–6 months, though the timeline varies widely.

When to Call a Doctor

Most crying is normal and not a sign of illness. But there are times when you should seek medical attention promptly.

In Japan, if you're worried, you can call the child health consultation line at #8000 (available in all prefectures; hours vary by prefecture but typically operate from early evening through the following morning — check your local municipality's website for exact times). For emergencies, call 119 (ambulance). If you are not sure whether the crying needs a doctor tonight or can wait until morning, our guide to deciding when a sick child needs care walks through that call.

📖 Japanese Vocabulary

Useful words when talking to a doctor or nurse about your baby's crying.