Most medications can cause side effects which can be defined as an unwanted response to a medication when it is taken in normal doses. Side effects can range from mild or severe, temporary or permanent. Side effects are not experienced all patients who take this medication. Many side effects can be managed, and others may go away over time. Stop using Altace and contact your doctor if you experience any of the following symptoms: Feeling like you might pass out, High potassium level (slow heart rate, weak pulse, muscle weakness, tingly feeling, Dry mouth, thirst, confusion, swelling, and urinating less than usual or not at all, Pale skin, dark colored urine, easy bruising or bleeding, Jaundice (yellowing of the skin or eyes), Fever, chills, body aches, flu symptoms, sores in your mouth and throat Less serious side effects may include: Cough, Tired feeling, headache, Dizziness, spinning sensation, Nausea, vomiting Immediately seek medical help if you experience signs of an allergic reaction including hives; difficulty breathing and swelling of your face, lips, tongue, or throat. This is not a complete list of side effects and others may occur. Call your doctor for medical advice about additional side effects that you may experience.