hi there i read your query... Regarding your question, yes stress can cause dizziness, nausea and weakness... stress downregulate your immune system and causes infections like common cold, throat infection etc... other symptoms also include palpitations, increased heart beats. shortness of breath... but u must need to rule out other conditions for these symptoms...and for that you require physical examination an other check ups by any physician. for stress u should try meditation and relaxation.. u can consult to the psychiatrist for the same.. try to be stressfree . have good sleep and diet.. hope it helps.. regards...