In the first days after birth, sudden tearfulness or a low mood that comes and goes is common. So is a tiredness that sits differently from ordinary exhaustion. Most of the time this is what's known as the baby blues, and it tends to pass within a couple of weeks. But postnatal depression is a separate experience, with a different timeline and different implications for how you feel and what kind of support helps. Knowing which one you're dealing with matters.1
What the baby blues feel like and why they happen
If you feel weepy, on edge, or quick to tears in the first days after birth, this is often the baby blues. They are a mild, short-lived stretch of low mood, tearfulness, and irritability. Up to 80% of new mothers go through them, and they are a normal reaction after childbirth.4
These feelings tend to arrive somewhere between three and ten days after giving birth. They come largely from the sharp hormonal shifts that follow delivery, mixed with broken sleep, physical recovery, and the adjustment to a new role. You may feel weepy for no clear reason, anxious, restless, or more easily moved than usual.2
What sets the baby blues apart is how quickly they pass. These feelings usually settle on their own within two weeks of birth. If you are in them right now, it may help to know the window is short. If they carry on past two weeks, that is when telling baby blues and postnatal depression apart starts to matter.5
When low mood is postnatal depression
Postnatal depression (PND) is a deeper and longer-lasting low than the baby blues. It affects more than 1 in 10 women in the year after childbirth, and partners and non-birthing parents can be affected too. If you are in that first year after birth and something feels persistently low, it is worth knowing what PND can look like.6
PND can build slowly or come on more suddenly, and it can start at any point in the first year after birth. It does not follow a fixed schedule. You might feel fine in the early weeks, then notice something shifting at two months, or four months, or later.7
Symptoms that point toward PND
PND usually brings a cluster of symptoms that stick around and start to affect daily life. You might notice:
- Persistent sadness or low mood that does not lift
- Loss of interest in things you usually enjoy
- Low energy and lasting tiredness beyond what newborn care alone explains
- Trouble concentrating or making decisions
- Difficulty sleeping even when your baby sleeps
- Feeling guilty, worthless, or unable to cope
- Difficulty bonding with your baby
In more severe cases, frightening thoughts about harming yourself or your baby can come up. These thoughts can come with PND. They are a sign that you need support, and support is available.8

The difference between baby blues and postnatal depression: duration and severity
The clearest way to tell the two apart is to watch how long the feelings last and how much they shape your day. If sadness, anxiety, or tearfulness carry on for more than two weeks after birth, PND becomes the more likely explanation. Two weeks is a guide, and you do not have to wait that long to speak to someone if what you are feeling is distressing.9
The baby blues tend to come and go and feel temporary. PND tends to feel heavier, more fixed, and harder to shake. With the baby blues, there are usually moments where you feel more like yourself. With PND, that relief is harder to find.3
When and how to seek support
Your postnatal appointments are partly there to check in on how you are feeling. You can expect to be asked about your emotional wellbeing at these visits, so bringing up how you feel is a normal and expected part of postnatal care.10
If symptoms last longer than two weeks, are getting worse, or feel too much to manage, speaking with your GP, midwife, or health visitor is an important step. Many are trained to spot PND and can point you toward the right support.11
PND is treatable. Support can include self-help approaches, talking therapies such as cognitive behavioural therapy (CBT, a structured form of talking therapy), and in some cases medication such as antidepressants. Recovery is possible with the right support, and any decisions about medication belong in a conversation with your doctor.12