Yes, the physical symptoms can be caused by thoughts that are running in our mind. As we have vastly discussed the stress we can focus on it as the thought that makes one restless and tensed and that indirectly and sometimes directly affects the physical body of a person. While we are feeling stressed the adrenal glands of our body releases the hormones, which is known as stress hormones along with adrenaline and cortisol which makes us feel the emotion and symptoms that is there to keep oneself in safety.