The Connection between Daylight Savings, Insomnia, and Hypertension

Daylight Saving Time (DST) is the practice of advancing clocks by one hour during the warmer months and returning them back one hour during the cooler months. The goal is to maximize exposure to natural daylight during the evening hours of spring and summer.

During DST, sunrise and sunset occur one hour later by the clock. While this provides more evening daylight, it also reduces morning light exposure—an important regulator of the body’s internal clock.

In the United States, DST begins on the second Sunday in March and ends on the first Sunday in November. Not all U.S. regions observe DST. Areas that do not include Hawaii, most of Arizona, Puerto Rico, Guam, American Samoa, the U.S. Virgin Islands, and the Northern Mariana Islands.

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Yes—evidence consistently shows a connection between DST and sleep disruption. According to sleep medicine research and circadian biology studies, the one-hour time shift can significantly disturb the body’s circadian rhythm, especially during the spring transition.

The circadian rhythm is the body’s internal 24-hour clock that regulates sleep, alertness, hormone release, metabolism, and blood pressure. It is highly sensitive to light exposure, particularly morning light.

When DST begins:

• Morning light exposure is reduced

• Evening light exposure increases

• Melatonin release is delayed

• Sleep onset becomes harder

• Sleep duration is often shortened

This mismatch between biological time and social schedules can trigger insomnia, fragmented sleep, and daytime fatigue—especially in people already prone to sleep disorders.

Because DST can make falling asleep harder, many people turn to melatonin supplements. While melatonin can be helpful in certain circadian rhythm disruptions, current medical guidance urges caution.

• Melatonin is not a sedative, but a hormone that signals sleep timing

• Incorrect timing or excessive dosing can worsen sleep quality

• Side effects may include vivid dreams, dizziness, grogginess, and next-day sedation

Sleep medicine organizations recommend:

• Using the lowest effective dose (often 0.5–3 mg)

• Avoiding long-term or nightly use without medical guidance

• Taking melatonin earlier in the evening, not at bedtime

For some individuals, improper use can actually prolong insomnia rather than resolve it.

Yes. DST has been associated with short-term increases in blood pressure, heart rate, and cardiovascular stress, particularly in the days following the spring time change.

Why Blood Pressure Is Affected

• Blood pressure naturally drops during sleep and rises upon waking

• Sleep deprivation shortens the restorative phase where blood pressure lowers

• Increased sympathetic nervous system activity raises heart rate and BP

• Stimulant use (coffee, energy drinks) often increases with fatigue

For people with hypertension, heart disease, diabetes, or sleep disorders, DST can temporarily increase cardiovascular risk if sleep loss is not addressed.

1. Adjust Your Sleep Schedule Early

• Shift bedtime and wake time 15–20 minutes earlier for several days before DST

• Maintain consistent sleep and wake times—even on weekends

2. Maximize Morning Light Exposure

• Get outside within the first hour of waking

• Open blinds immediately in the morning

• Limit bright light exposure at night

3. Be Cautious With Sleep Aids

If using melatonin or other sleep aids:

• Consult a medical professional

• Follow recommended dosing

• Avoid combining with alcohol or sedatives

• Monitor for side effects

4. Use Relaxation Techniques

Effective options include:

• Deep breathing

• Meditation

• Muscle relaxation

• Yoga or Tai Chi

• Prayer or quiet reflection

5. Monitor Blood Pressure

If you have hypertension:

• Check blood pressure during the week after DST

• Stay hydrated

• Limit caffeine late in the day

• Maintain medication adherence

6. Seek Professional Guidance

Persistent insomnia, fatigue, or blood pressure changes deserve medical evaluation. Telehealth providers can help assess sleep patterns, medication timing, and cardiovascular risk during seasonal transitions.