Thank you for the opportunity to help you with your question!
Symptoms are physical or mental features which the patient can tell the doctor or can see like headache or a rash and no instruments are required whereas signs are indicators of a medical conditions that can be observed objectively or measured using tests or instruments e.g blood pressure or blood sugar and the patient does not notice it. Syndromes are typical constellations/presentations of laboratory and physical findings that may be seen as part of a primary disease process.
Please let me know if you need any clarification. I'm always happy to answer your questions.