The machine will treat obstructive sleep apnoea by maintaining the prescribed airway pressure whether a humidifier is used or not. However, humidification can make a significant difference to comfort—and that can improve the overall success of CPAP therapy.

CPAP delivers a continuous flow of air throughout the night. For some people, particularly those using higher pressures or sleeping in a dry or air-conditioned room, this airflow can cause a dry mouth, blocked or irritated nose, sore throat, coughing or nasal congestion. A heated humidifier adds moisture to the airflow, helping reduce these symptoms.

When CPAP feels more comfortable, people are generally more likely to keep their mask on and use the machine consistently. Because regular nightly use is essential for effective treatment, a humidifier may indirectly improve treatment results by supporting better adherence.

Humidity should be adjusted to suit the individual. Too little moisture may not relieve dryness, while too much can cause condensation—or “rainout”—inside the tubing and mask. A heated tube can help maintain the air temperature and reduce condensation. Mask leakage and mouth breathing should also be checked rather than assuming every dryness problem requires more humidity.

Use the type of water recommended by your machine’s manufacturer, empty the chamber each morning, and clean it regularly.

In short, a humidifier does not change the therapeutic pressure of your CPAP machine, but it can make treatment considerably more comfortable and easier to use every night.

However, leg movements can continue and may become more noticeable once apnoea-related awakenings are reduced. Persistent restlessness, kicking or disrupted sleep despite good CPAP results should therefore be discussed with a doctor.

Iron deficiency is an important reversible contributor to RLS. Treatment may involve oral or intravenous iron after ferritin and transferrin saturation have been assessed. Iron should not be started solely because of symptoms without appropriate testing and professional advice.

Medicines such as gabapentin or pregabalin may reduce RLS symptoms, but they can also cause dizziness, unsteadiness and daytime drowsiness. These effects may be more important in older adults and people taking opioids, sleeping tablets or other sedating medicines. Because gabapentinoids can sometimes suppress breathing, the prescriber should know if the patient has sleep apnoea—even when CPAP is being used.

Dopamine agonists, including pramipexole and ropinirole, can cause nausea, sleepiness and, occasionally, sudden sleep episodes or impulse-control problems. Long-term use may also cause “augmentation,” where symptoms begin earlier, become more severe or spread to other parts of the body. Increasing the dose without medical review can make this cycle worse.

People using both CPAP and RLS medication should continue CPAP consistently and monitor sleepiness, leg symptoms and medicine side effects. Never stop an RLS medicine suddenly without advice. If symptoms persist despite effective CPAP, or daytime drowsiness worsens after starting medication, speak with the prescribing doctor or sleep specialist so both conditions can be reviewed together.

Book an appointment to discuss any medication related issues.

CPAP Quiz of the Month

💤 CPAP Adelaide Sleep Quiz

Restless Legs Syndrome Quiz

Sam experiences uncomfortable, restless feelings in his legs at night that improve when he walks. He also snores loudly, feels tired during the day and sometimes appears to stop breathing while asleep. What is the best next step?

1. Wait until the symptoms become painful before seeking advice

2. Discuss both problems with his GP and ask whether blood tests and a sleep study are appropriate

3. Assume the leg symptoms are caused entirely by sleep apnoea

4. Start taking iron without having any blood tests