What are the reasons that cold medicine can cause low blood pressure?

Aug 27, 2025 Source: Cainiu Health

Dr. Tian Hongbo

Introduction

Under normal circumstances, the main causes of hypotension resulting from cold medications include drug ingredients that dilate blood vessels, insufficient water intake after taking medication, dehydration, heart failure, and hypothyroidism. If symptoms of hypotension occur, it is recommended to seek timely medical treatment at a正规 hospital. In daily life, it is important to carefully read the ingredient list before taking cold medications.

Generally, the main causes of hypotension induced by cold medications include drug ingredients dilating blood vessels, insufficient water intake after taking medication, dehydration, heart failure, and hypothyroidism. If symptoms of hypotension occur, it is recommended to seek timely medical treatment at a regular hospital. The specific analysis is as follows:

1. Drug Ingredients Dilating Blood Vessels

Certain cold medications contain ingredients such as pseudoephedrine and chlorpheniramine. Although pseudoephedrine can relieve nasal congestion, excessive dosage or administration to sensitive individuals may dilate peripheral blood vessels, leading to decreased blood pressure. It is essential to strictly follow the prescribed dosage instructions and avoid overdosing. If symptoms such as dizziness and fatigue occur after taking the medication, appropriate rest in a supine position can help increase venous return and alleviate hypotensive symptoms.

2. Insufficient Water Intake After Taking Medication

Consuming too little water while taking cold medication may reduce blood volume. Particularly, cold medications may cause mild perspiration, further exacerbating hypovolemia and inducing hypotension. It is necessary to ensure a daily water intake of 1500-2000 milliliters during medication, drinking in small amounts frequently to maintain normal blood volume and prevent hypotension.

3. Dehydration

Colds accompanied by fever or vomiting can easily lead to dehydration. If fluid replacement is not timely during cold medication administration, it may cause severe hypovolemia, reducing intravascular pressure and inducing hypotension. It is necessary to follow medical advice and promptly replenish electrolyte solutions, such as Oral Rehydration Salts III or Compound Sodium Chloride Injection. In cases of severe dehydration, intravenous fluid replacement therapy is required to rapidly restore blood volume.

4. Heart Failure

Individuals with weakened cardiac pumping function may experience an increased cardiac burden from certain ingredients in cold medications, affecting blood pressure regulation and causing hypotension. Under medical guidance, drugs such as Nitroglycerin Tablets, Isosorbide Mononitrate Sustained-Release Tablets, and Aspirin Enteric-Coated Tablets can be used to improve cardiovascular function. Consultation with a physician before taking cold medications is necessary to select drugs with minimal impact on blood pressure.

5. Hypothyroidism

Patients with hypothyroidism have slow metabolism and weaker blood pressure regulation. Cold medications may further inhibit metabolism, affecting vascular constriction function and causing hypotension. Under medical guidance, thyroid hormone supplements such as Levothyroxine Sodium Tablets, Thyroid Tablets, and Levotiroxine Tablets can be used to improve metabolic status. Regular monitoring of thyroid function and blood pressure is necessary during medication.

In daily life, it is important to carefully read the ingredient list before taking cold medications, especially for individuals with underlying medical conditions who should consult a physician. Maintain regular meals during medication and avoid taking medication on an empty stomach. Monitor blood pressure changes and rest promptly if symptoms such as dizziness or palpitations occur. Keep warm during a cold, avoid excessive fatigue, and promote physical recovery.

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What should people with low blood pressure eat?

In general, people with hypotension can consume foods such as longan, red dates, lean meat, eggs, and spinach. They may also take medications such as Shengmai Yin Oral Liquid, Yiqi Yangxue Oral Liquid, Midodrine Hydrochloride Tablets, Shenqi Shengyang Buxue Capsules, and Huangqi Jing Oral Liquid according to medical advice for regulation. Additionally, they should maintain regular作息 (作息 should be translated as "daily routine" or "作息" could be removed if not needed), avoid sudden changes in body position, and increase water intake appropriately.

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What is the best medication for insufficient cerebral blood supply?

Generally speaking, there is no such thing as a single "best medication for insufficient cerebral blood supply." The main causes of inadequate brain blood flow include chronic sleep deprivation, mental stress, cerebral arteriosclerosis, cervical spondylosis, and low blood pressure. Patients should follow their doctor's instructions and choose appropriate medications based on their specific conditions, such as enteric-coated aspirin tablets, flunarizine hydrochloride capsules, or ginkgo leaf extract tablets.

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Can taking cold medicine cause a delayed menstrual period?

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