Tremor and disease activity/intensity can worsen in response to fatigue, strong emotions, low blood sugar, cold and heat, caffeine, lithium salts, some antidepressants, and other factors. Typically, the tremor worsens in "performance" situations, such as when writing a cheque for payment at a store or giving a presentation.Parkinsons disease and parkinsonism can also occur simultaneously with ET. The degree of tremor, rigidity, and functional disability did not differ from patients with idiopathic Parkinsons disease. Hand tremor predominated (as it did in Parkinsons disease), and occurred in nearly all cases, followed by head tremor, voice tremor, neck, face, leg, tongue, and trunk tremor. Most other tremors occurred in association with hand tremor. More severe tremors, a lower sleep disorder frequency, and a similar prevalence of other non-motor symptoms also can occur.Walking difficulties in essential tremor are common. About half of patients have associated dystonia, including cervical dystonia, writers cramp, spasmodic dysphonia, and cranial dystonia, and 20% of the patients had associated parkinsonism. Olfactory dysfunction (loss of sense of smell) is common in Parkinsons disease, and has also been reported to occur in patients with essential tremor. A number of patients with essential tremor also exhibit many of the same neuropsychiatric disturbances seen in idiopathic Parkinsons disease.Essential tremor with tremor onset after the age of 65 has been associated with mild cognitive impairment, as well as dementia; although the link between these conditions, if any, is still not understood.Essential tremor has two tremor components,  central and peripheral.
Signs and symptoms
The signs and symptoms of non-Hodgkin lymphoma vary depending upon its location within the body. Symptoms include enlarged lymph nodes, fever, night sweats, weight loss, and tiredness. Other symptoms may include bone pain, chest pain, or itchiness. Some forms are slow growing, while others are fast growing. Enlarged lymph nodes may cause lumps to be felt under the skin when they are close to the surface of the body. Lymphomas in the skin may also result in lumps, which are commonly itchy, red, or purple. Lymphomas in the brain can cause weakness, seizures, problems with thinking, and personality changes.While an association between non-Hodgkin lymphoma and endometriosis has been described, these associations are tentative. Causes
The many different forms of lymphoma probably have different causes. These possible causes and associations with at least some forms of NHL include:

Infectious agents:
Epstein–Barr virus: associated with Burkitts lymphoma, follicular dendritic cell sarcoma, extranodal NK-T-cell lymphoma and diffuse large B-cell lymphoma. Human T-cell leukemia virus: associated with adult T-cell lymphoma. Helicobacter pylori: associated with gastric lymphoma. HHV-8: associated with primary effusion lymphoma, multicentric Castleman disease. Hepatitis C virus: associated with splenic marginal zone lymphoma, lymphoplasmacytic lymphoma and diffuse large B-cell lymphoma. HIV infection. Some chemicals, like polychlorinated biphenyls (PCBs), diphenylhydantoin, dioxin, and phenoxy herbicides. Medical treatments, like radiation therapy and chemotherapy. Genetic diseases, like Klinefelter syndrome, Chédiak–Higashi syndrome, ataxia–telangiectasia syndrome. Autoimmune diseases, like Sjögren syndrome, celiac disease, rheumatoid arthritis, and systemic lupus erythematosus. Bone trauma and microfractures associated with diffuse large B-cell lymphoma originating in bone marrow.