Introduction

Nocturia is the awakening from sleep 2 or more times at night to urinate. The awakenings caused by nocturia result in significant sleep disruption and fatigue during the daytime. Interrupted sleep may induce sleep disorders, particularly in elderly patients such as sleep apnea, and are the common reason for awakenings during night sleep.¹ The causes responsible for nocturia are complex and various medical conditions such as polyuria (during day or nighttime), low bladder capacity or overactive bladder, ageing, and benign prostatic obstruction (men) increase its occurrence.

Chronic clinical conditions including diabetes mellitus, diabetes insipidus, anorexia nervosa, congestive heart failure, and use of medications like diuretics and analgesics also increase urination frequency thus strengthening nocturia. Sleep disorders are defined as conditions that affect the ability of the body to rest and maintain wakefulness. There are more than 80 sleep disorders and insomnia, sleep apnea, and restless leg syndrome are more common. 

The rising prevalence of nocturia and sleep disorders proposes that sleep disorders may be inducing some awakenings from sleep usually attributed by patients with nocturia. However, it is important to note that nocturia associated with sleep disorders would differ reasonably from nocturia associated with pressure to urinate. These are caused by regular medical disorders and are diagnosed and treated differently.² 

Nocturia increases with age and is more common in elderly patients aged 60 years or more. It correlates with a higher incidence of falls at night diminished quality of life, fractures, and sometimes death.³ We will discuss common sleep disorders, their relation with nocturia, and treatment measures.

Types of sleep disorders associated with nocturia

In the cases of self-reported insomnia and declining sleep quality, nocturia appeared as an independent responsible factor. Nocturia was found to be related particularly to difficulty in falling asleep. A study revealed that nocturia was linked to fewer total sleeping hours and difficulty falling back to night sleep. 

People with sleep disorders wake up frequently and feel that their bladder fills easily resulting in instances of nocturia.⁴ Thus sleep disorders contribute to nocturia, but the association between the two is usually neglected. The sleep disorders related to nocturia include:

Insomnia

Insomnia is one of the major prevailing chronic disorders in the general population, affecting nearly 15% of adults.⁵ Chronic insomnia is the difficulty of falling asleep or continuing sleep and is commonly found in aged people (~ 10–15% prevalence). In several epidemiological analyses and clinical studies, the impact of the relationship between nocturia and insomnia in patients has been reported.⁶ 

In men, the high prevalence of obstructive sleep apnea or benign prostatic hyperplasia may promote joint nocturia/insomnia morbidity. This can be characterised as sleep onset insomnia (difficulty in falling asleep), sleep maintenance insomnia (frequent awakenings at night-time), and early morning insomnia (early morning awakening and inability to return to sleep). Among these, sleep maintenance insomnia is frequently reported by older adults. 

Sleep apnea

Awakening from sleep is mostly attributed to patients due to the urge to urinate as a result of sleep disorders, especially sleep apnea.⁷ Obstructive sleep apnea (OSA) defined as a disorder is caused by partial, complete, or repetitive obstruction of the upper airways. Often it is associated with hypoxemia (low blood oxygen saturation). Symptoms include snoring, excessive daytime sleepiness, dry mouth, headache, or sweating. 

Obstructive sleep apnoea (OSA) causes nocturnal polyuria leading to increased bladder signals. Nocturia in OSA is prevalent in 48% to 76% of patients. The increase in severity of OSA is reported with the rise in the frequency of nocturia. It has been found that in patients with OSA, the frequency of nocturia is significantly more than in healthy individual controls. A decline in nocturia was reported when OSA was treated with continuous positive airway pressure (CPAP). 

Restless legs syndrome (RLS)

Restless legs syndrome (RLS) or Willis-Ekbom disease induces a strong urge for leg movement. This urge is usually caused by an uncomfortable or unbearable feeling in the legs and moving the legs eases the discomfort for a while. Often it happens while sitting or lying down in the evening or at night. It may begin at any age and get worse with age. 

Consequently, the discomfort and urge to move the legs influence the depth of sleep or disrupt it. Frequent awakening from sleep can cause sensations in the bladder to void (go for urination) and contribute to nocturia. Lifestyle changes, self-care steps, and medicines can help relieve symptoms of RLS.

Periodic limb movement disorder (PLMD)

Periodic limb movement disorder (PLMD) is the repetitive limb movements during sleep. It occurs with restless legs syndrome (RLS). PLMD is diagnosed only in patients complaining about sleep with evidence of Periodic limb movements during sleep (PLMS) but in the unavailability of other sleep disorders.⁸

PLMD is as rare as uncommon PLMS. Unlike insomnia, RLS and PLMD have been rarely discussed with nocturia. Some studies demonstrated the link between PLMS and nocturia induced by a disturbance in sleep initiation. However, urologists have communicated rare complaints of PLMD from patients with nocturia at night. The treatment of RLS may also help to reduce symptoms of PLMD.

Physical and psychological impacts

A survey conducted by the National Sleep Foundation of the United States revealed the predominance of nocturia among older age groups (55-84 years), self-reporting insomnia, and 53% perceived nocturia as the reason for disturbed sleep at night.⁹ The synergy between awakening at night and nocturia has adverse impacts on one’s life which are given below.

Daytime fatigue

• Waking up at night causes persistent tiredness and lethargy
• Reduced daytime functioning and daily activities due to less quality sleep
• The association of poor sleep and nocturia with poor health can also change over time

Cognitive impairment

• Disturbed sleep will hinder one’s ability to focus and concentrate. 
• An association between sleep and nocturia affects memory and other related problems.

Mood disturbances

• Lack of good quality sleep increases irritability and stress among all age groups
• A study in Sweden revealed nocturia escalates poor mental health among participants 20-64 years of age
• Improper sleep induces irritation and stress and decreases life satisfaction and social participation
• The higher risk of depression in men with nocturia is twice that of women affected with nocturia

Reduced quality of life

• Improper sleep or nocturnal awakening diminishes daytime activity resulting in imbalances in physical and mental health
• Interrupted sleep has adverse repercussions and affects the quality of life (QoL)
• The decline in sleep quality indirectly induces factors associated with poor health such as hypertension and diabetes
• In elderly people aged 60 years or above, the relationship between death and nocturia is initiated by sleep issues causing instances of falls and fractures leading to death

A survey conducted on participants aged 18 years or above demonstrated that 75% of participants reported the urge to go to the bathroom as the main cause of waking up at night.¹⁰ Thus, the impacts of nocturia and sleep disorders require treatment measures (discussed below) to improve the quality of life.

Treatment measures

The association of nocturia and sleep disorder has adverse impacts on the physical and mental life of patients leading to a decline in the quality of life. The root cause of nocturia or sleep disorder should be diagnosed before taking any treatment measures.¹¹ Nocturia and waking at night are considered a normal part of ageing in elderly people and neglected by adults requiring attention. Consequently, the adverse effects of nocturia and sleep disorder should be reduced using medical interventions, changes in lifestyle, and behaviour alongside psychological support which are given below.

Medical interventions

Nocturia may improve with the treatment by diagnosing and treating the underlying problems causing it. If the condition is the predominant reason for nocturia in that patient, an effective treatment leads to good compliance results. For instance, OSA which is recognised to induce nocturia can be reduced by continuous positive airway pressure (CPAP). Unfortunately, the inability of many patients to tolerate CPAP therapy leads to not using this as a treatment reliably. Hence patients should be diagnosed accurately for the cause so that prescribed medications by clinicians yield better results.

• Medicines like desmopressin help the kidneys to produce less urine
• Diuretic medicines like bumetanide can be used to regulate urine production and high blood pressure
• Anticholinergic or beta-agonist medicines can be used to treat bladder muscle problems which relax the bladder and correct the overactive bladder

Behavioural strategies

If medications alone do not aid in treating nocturia, then some behavioural strategies may help. Patients often change from one type of medicine to another, until they find something suitable for the treatment. In such instances, changes in behaviour including recommendations about fluid intake and bladder training exercises will not assist in relieving the symptoms. In some cases, fluid intake advice may conflict with other conditions. For instance, reducing fluid intake is not good for patients with a history of kidney stones or any condition causing fluid loss. Some measures are listed below which can be adopted as measures to control it:

• Limiting fluid intake for people who consciously consume large quantities of water for a healthy lifestyle
• Diuretics for water retention and subclinical salt can sometimes be used short-term in patients with nocturia. However, some urologists do not consider this norm
• Leg elevation is usually recommended in the evening for dependent oedema or peripheral oedema and patients with heart failure. Elevating the leg helps to redistribute fluids back into the bloodstream and thus reduces the urge for urination

Lifestyle modifications

The treatment of nocturia and sleep disorders as discussed above provides some relief. Psychological support such as support from relatives, stress management techniques to relax the brain for sleep, and other Cognitive-behavioural therapy (CBT) help to recover rapidly. With changes in lifestyle and paying attention to other health problems, symptoms get improved and would help to sleep well again.

• Manage the use of diuretics: Take them at least 6 hours before sleeping. It will help to reduce urination times during night hours
• Regulate fluid intake at night or evening: Drink ample fluids during the day (especially water) and restrict fluid consumption 2-4 hours before sleep
• Restrict the limit of alcohol and caffeine such as soda, tea, and coffee
• Use compression socks: Here elastic compression stockings will prevent fluid build-up by putting pressure on the legs
• Appreciate afternoon naps: Nocturnal awakening (or waking up at night) causes poor sleep then a nap can help to feel better during the day. Naps help in the absorption of liquids into the bloodstream. However, be careful about the nap duration. It shouldn’t be too long or too often, because inappropriate naps may disrupt nighttime sleep patterns
• Adjust the sleep environment and abide by sleep hygiene practices for uninterrupted sleep

Summary

Nocturia is a condition that causes awakening from sleep two or more times affecting all age groups. However, it is significantly harmful in elderly people due to its occurrence with other age-related illnesses resulting in falls, fractures, and death. Sleep disorders such as apnea, insomnia, RLS, and PLMD cause awakening at night which induces a need to urinate. The instances of awakening from sleep at night increase with age and are more prevalent after the 60s. This contributes to the rise in the frequency of urination or nocturia. Its association with other diseases like hypertension and coronary heart disease enhances it further. 

Therefore proper guidance and medications should be considered along with behaviour and lifestyle modifications. Proactive interventions to improve sleep quality have to be considered to prevent nocturia and a good quality of life. If the behavioural and lifestyle changes are ignored a healthy life may not be possible.