Why does your Shoulder hurt at night? 7 possible causes

You finally get into bed after a long day, hoping to switch off. Then your shoulder starts aching. You turn onto the other side, adjust your pillow and try sleeping on your back but somehow, you still can't get comfortable.

If shoulder pain seems worse at night, you're not imagining it. Night-time discomfort can affect more than your shoulder. It can disturb your sleep, lower your energy and impact how you feel the following day. In fact, research shows that the prevalence of sleep disturbance in patients with rotator cuff issues is exceptionally high, ranging from 70% to 89%.

Here is a look at why your shoulder might be keeping you awake and what you can do about it.

1. Your Sleeping Position is Compressing the Joint

The position you sleep in can make a significant difference. If you regularly sleep on the painful side, your body weight may place additional pressure around an already sensitive shoulder, compressing structures like the rotator cuff tendons and the bursa.

To find a more comfortable position, try:

• Avoiding putting direct pressure on the painful side.

• Supporting your arm with a pillow to keep the shoulder in a neutral position, which reduces tension on the rotator cuff.

• Trying different sleeping positions.

• Avoiding positions that consistently increase your symptoms.

There isn't one perfect sleeping position for everyone. The aim is to find a position that feels comfortable for you.

2. Your Shoulder is Reacting to a Busy Day

For many common conditions, your shoulder doesn't suddenly become painful when you go to bed. The activities you've done throughout the day can influence how it feels later.

You may not notice much discomfort while you're busy. Once you're lying still, however, the shoulder can become much more noticeable as the tissues respond to the day's physical loads. Paying attention to what you've done during the day can help you recognise patterns.

3. You May Be Avoiding Movement Because It Hurts

When something hurts, protecting it is a natural response. You might stop reaching overhead, use your other arm more or avoid movements that cause discomfort.

Some activity modification can be sensible, but avoiding movement completely for too long may contribute to stiffness and make returning to normal activities more difficult. The aim isn't to push through significant pain. It's about finding an appropriate level of movement and gradually building your shoulder's tolerance.

4. Night-Time Stillness Highlights Stiffness

During the day, you're naturally changing position and using your arms. At night, you're relatively still for several hours.

For some people, this can make shoulder stiffness more noticeable, particularly when changing position or getting up in the morning. If stiffness is persistent or increasingly affecting your sleep, it's worth paying attention to rather than simply accepting it as normal.

5. Your Evening Routine Could Be Contributing

Think about what happens during the hours before bed. You might be:

• Working on a laptop.

• Using your phone for long periods.

• Watching television in one position.

• Exercising later in the evening.

These activities aren't necessarily harmful, but if your shoulder is already irritated, prolonged or repetitive positions may contribute to discomfort. Noticing what makes your symptoms better or worse can help you make more informed changes.

6. The Frustrating Sleep-Pain Cycle

Shoulder pain can disturb your sleep. But poor sleep can also make it harder to cope with discomfort the following day. Clinical studies demonstrate a strong, bidirectional relationship between sleep and pain: sleep deprivation actively lowers the central nervous system's pain threshold, making you more physically sensitive to discomfort.

You may wake up feeling:

• Tired and less energetic.

• More sensitive to discomfort.

• Less motivated to exercise or stay active.

This can create a frustrating cycle where pain affects sleep, and poor sleep makes the pain feel harder to manage. That's why persistent night-time shoulder pain shouldn't simply be dismissed.

7. When Should You Seek Professional Advice?

Occasional discomfort after a particularly active day isn't necessarily a cause for concern. However, it's worth getting your shoulder assessed if:

• Pain has continued for several weeks.

• You're regularly waking during the night.

• Your shoulder movement is becoming restricted.

• You notice weakness.

• Symptoms are getting progressively worse.

• The pain started after an injury.

A professional assessment can help you understand what's contributing to your symptoms and whether further treatment or rehabilitation is appropriate.

What Can You Try Tonight?

You don't necessarily need to completely change your routine. Start with a few simple steps:

• Find a comfortable sleeping position.

• Support your arm if needed.

• Avoid putting direct pressure on the painful shoulder.

• Notice which daytime activities aggravate your symptoms.

• Keep your shoulder moving within a comfortable range.

If the problem continues, don't keep guessing. Understanding what's contributing to your symptoms is a better starting point than simply trying to work around the pain.

When Shoulder Pain Starts Affecting Your Sleep

If shoulder pain is regularly disturbing your sleep, it's worth looking beyond temporary ways to manage the discomfort.

The right physiotherapy can help identify what's contributing to your symptoms, improve shoulder movement and rebuild strength through personalised rehabilitation. If your shoulder pain is affecting your sleep or everyday life, Xcel Health can help you take the next step towards a more comfortable recovery.

References:

• Lin, X., et al. (2024). Analysis of related factors influencing the sleep quality in patients with rotator cuff tears. Frontiers in Surgery. (Highlights that the prevalence of sleep disturbance in patients with rotator cuff pathology ranges from 70.2% to 89%).

• Koffel, E., et al. (2016). The Bidirectional Relationship Between Sleep Complaints and Pain. The Clinical Journal of Pain. (Provides evidence on how sleep deprivation lowers pain thresholds and creates a cyclical relationship with chronic musculoskeletal pain).